.
| Name of unit
| Symbol
| Relation to SI units
|
| Length, l
|
| metre (SI base unit)
| m
| ≡ m
|
| Fermi
| fm
| ≡ 10-15 m = 1 fm
|
| x unit; siegbahn
| xu
| ≈ 1.0021×10-13 m
|
| stigma
|
| ≡ 1×10-12 m = 1 pm
|
| Bohr radius
| a0; b
| ≡ α/(4πR∞;) ≈ 5.291 772 083×10-11 ± 19×10-20 m
|
| atomic unit of length
| au
| ≡ a0 ≈ 5.291 772 083×10-11 ± 19×10-20 m
|
| ångström
| Å
| ≡ 10-10m = 0.1 nm
|
| micron
| μ
| ≡ 10-6m = 1 μm
|
| twip
| twp
| ≡ 1/1440 in ≈ 1.763 889×10-5 m
|
| mil; thou
| mil
| ≡ 10-3 in = 2.54×10-5 m
|
| mickey
|
| ≡ 1/200 in = 1.27×10-4 m
|
| calibre
| cal
| ≡ 1/100 in = 0.254 mm
|
| point (ATA)
| pt
| ≡ 0.013837 in = 0.351 459 8 mm
|
| point (PostScript)
| pt
| ≡ 1/72 in ≈ 0.352 778 mm
|
| point (metric)
| pt
| ≡ 3/8 mm = 0.375 mm
|
| point (Didot; European)
| pt
| ≡ 0.376 065 mm
|
| line
| ln
| ≡ 1/12 in ≈ 2.116 667 mm
|
| line (Paris) ["ligne"]
| l
| ≡ 1/12 p = 1/443.296 m ≈ 2.255 829 mm
|
| line (Quebec) ["ligne"]
| l (Qc)
| ≡ 1/12 p (Qc) = 2.255 837 5 mm
|
| barley corn
|
| ≡ 1/3 in ≈ 8.466 667 mm
|
| finger
|
| ≡ 7/8 in = 22.225 mm
|
| inch
| in
| ≡ 1/36 yd = 25.4 mm
|
| U.S. survey inch
| in
| ≡ 1/12 U.S. survey foot = 100/3937 m ≈ 25.400051 mm
|
| inch (Paris) ["pouce"]
| p
| ≡ 1/12 P = 1/(36 + 11.296/12) m ≈ 27.069 949 mm
|
| inch (Quebec) ["pouce"]
| p (Qc)
| ≡ 1/12 P (Qc) = 27.070 05 mm
|
| stick
|
| ≡ 2 in = 50.8 mm
|
| nail (cloth)
|
| ≡ 2 1/4 in = 57.15 mm
|
| palm
|
| ≡ 3 in = 76.2 mm
|
| hand
|
| ≡ 4 in = 0.1016 m
|
| finger (cloth)
|
| ≡ 4 1/2 in = 0.1143 m
|
| span
|
| ≡ 6 in = 0.1524 m
|
| link (Gunter's)
| lnk
| ≡ 66/100 ft = 0.201 168 m
|
| span (cloth)
|
| ≡ 9 in = 0.2286 m
|
| quarter
|
| ≡ 1/4 yd = 0.2286 m
|
| link (Ramden's; Engineer's)
| lnk
| ≡ 1 ft = 0.3048 m
|
| foot (Clarke's; Cape)
| ft (Cla)
| ≈ 0.304 797 265 4 m
|
| foot (Sear's)
| ft (Sear)
| ≈ 0.304 799 47 m
|
| foot (Indian)
| ft Ind
| ≈ 0.304 799 514 m
|
| foot (Benoît)
| ft (Ben)
| ≈ 0.304 799 735 m
|
| foot
| ft
| ≡ 12 in = 0.3048 m
|
| foot (American; U.S. Survey)
| ft (US)
| ≡ 1200/3937 m ≈ 0.304 800 610 m
|
| foot (Paris) ["pied"]
| P
| ≡ 1/(3 + 11.296/144) m ≈ 0.324 839 385 m
|
| foot (Quebec) ["pied"]
| P (Qc)
| ≡ 1.06575 ft = 0.324 840 6 m
|
| cubit
|
| ≡ 18 in = 0.4572 m
|
| pace
|
| ≡ 2 1/2 ft = 0.762 m
|
| yard
| yd
| ≡ 3 ft = 0.9144 m
|
| ell
| ell
| ≡ 45 in = 1.143 m
|
| fathom
| fm
| ≡ 6 ft = 1.8288 m
(sometimes ≡ 1/1000 NM = 1.852 m)
|
| rod; pole; perch
| rd
| ≡ 16 1/2 ft = 5.0292 m
|
| rope
| rope
| ≡ 20 ft = 6.096 m
|
| chain (Gunter's)
| ch
| ≡ 66 ft = 20.1168 m
|
| chain (Ramden's; Engineer's)
| ch
| ≡ 100 ft = 30.48 m
|
| arpent (Paris)
| arp
| ≡ 180 P = 25 920/443.296 m ≈ 58.471 089 m
|
| arpent (Quebec)
| arp (Qc)
| ≡ 180 P (Qc) = 58.471 308 m
|
| cable length (International)
|
| ≡ 1/10 NM = 185.2 m
|
| cable length (Imperial)
|
| ≡ 608 ft = 185.3184 m
|
| furlong
| fur
| ≡ 660 ft = 201.168 m
|
| cable length (U.S.)
|
| ≡ 720 ft = 219.456 m
|
| mile
| mi
| ≡ 1760 yd = 5280 ft = 1609.344 m
|
| mile (American; Statute; U.S. Survey)
| mi
| ≡ 5280 ft (US) = 5280×1200/3937 m ≈ 1609.347 219 m
|
| nautical mile
| NM; nm
| ≡ 1852 m
|
| nautical mile (Admiralty)
| NM (Adm); nm (Adm)
| ≡ 6080 ft = 1853.184 m
|
| geographical mile
| mi
| ≡ 6082 ft = 1853.7936 m
|
| telegraph mile
| mi
| ≡ 6087 ft = 1855.3176 m
|
| league
| lea
| ≡ 3 mi = 4828.032 m
|
| statute league
| lea
| ≡ 3 mi (US) ≈ 4828.041 656 m
|
| nautical league
| NL; nl
| ≡ 3 NM = 5556 m
|
| light-second
|
| ≡ 2.997 924 58×108 m
|
| light-minute
|
| ≡ 60 light-seconds = 1.798 754 748×1010 m
|
| astronomical unit
| AU
| = 149 597 870.691 ± 0.030 km
|
| spat
| S
| ≡ 1012 m = 1 Tm
|
| light-hour
|
| ≡ 60 light-minutes = 1.079 252 848 8×1012 m
|
| light-day
|
| ≡ 24 light-hours = 2.590 206 837 12×1013 m
|
| light-year
| l.y.
| ≡ c0×86 400×365.25
= 9.460 730 472 580 8×1015 m
|
| parsec
| pc
| ≈ 180×60×60/π AU
≈ 206 264.806 25 AU
= 3.261 563 776 9 ± 6×10-10 light-years
= 3.085 677 581 3×1016 ± 6×106 m
|
| Name of unit
| Symbol
| Relation to SI units
|
| Area, A
|
| square metre (SI unit)
| m²
| ≡ 1 m × 1 m
|
| barn
| b
| ≡ 10-28 m²
|
| circular mil; circular thou
| circ mil
| ≡ π/4 mil² ≈ 5.067 075×10-10 m²
|
| square mil; square thou
| sq mil
| ≡ 1 mil² = 6.4516×10-10 m²
|
| circular inch
| circ in
| ≡ π/4 in² ≈ 5.067 075×10-4 m²
|
| square inch
| sq in
| ≡ 1 in² = 6.4516×10-4 m²
|
| board
| bd
| ≡ 1 in × 1 ft = 7.741 92×10-3 m²
|
| square link
| sq lnk
| ≡ 1 lnk² = 4.046 856 422 4×10-2 m²
|
| square foot
| sq ft
| ≡ 1 ft² = 9.290 304×10-2 m²
|
| square yard
| sq yd
| ≡ 1 yd² = 0.836 127 36 m²
|
| cord
|
| ≡ 192 bd = 1.486 448 64 m²
|
| boiler horsepower equivalent direct radiation
| bhp EDR
| ≡ 1 sq ft × 1 bhp / 240 BTUIT/h ≈ 12.958 174 m²
|
| square rod/pole/perch
| sq rd
| ≡ 1 rd² = 25.292 852 64 m²
|
| are
| a
| ≡ 100 m²
|
| square chain
| sq ch
| ≡ 1 ch² = 404.685 642 24 m²
|
| dunam
|
| ≡ 1000 m²
|
| rood
| ro
| ≡ 1/4 ac = 1011.714 105 6 m²
|
| acre
| ac
| ≡ 10 sq ch = 4840 sq yd = 4046.856 422 4 m²
|
| hectare
| ha
| ≡ 10 000 m² = 0.01 km²
|
| yardland
|
| ≡ 30 ac = 1.214 056 926 72×105 m²
|
| hide
|
| ≡ 100 ac = 4.046 856 422 4×105 m²
|
| square kilometre
| km²
| ≡ 1 km² = 106 m²
|
| square mile; section
| sq mi
| ≡ 1 mi² = 2.589 988 110 336×106 m²
|
| square statute mile; square U.S. Survey mile
| sq mi
| ≡ 1 mi (US)² ≈ 2.589 998×106 m²
|
| township
|
| ≡ 36 sq mi (US) ≈ 9.323 994×107 m²
|
| barony
|
| ≡ 4000 ac = 1.618 742 568 96×107 m²
|
| Name of unit
| Symbol
| Relation to SI units
|
| Volume, V
|
| cubic metre (SI unit)
| m³
| ≡ 1
|
| litre
| L
| ≡ 1 dm³
|
| lambda
| λ
| ≡ 1 mm³ = 1 μL
|
| drop (metric)
|
| ≡ 1/20 mL = 0.05 mL
|
| minim (Imperial)
| min
| ≡ 1/480 fl oz = 1/60 fl dr ≈ 0.059 193 880 208 333 mL
|
| minim (U.S.)
| min
| ≡ 1/480 US fl oz = 1/60 US fl dr = 0.061 611 519 921 875 mL
|
| drop (U.S.)
| gtt
| ≡ 1/360 US fl oz ≈ 0.082 148 693 229 167 mL
|
| dram (Imperial fluid); Imperial fluidram
| fl dr
| ≡ 1/8 fl oz = 3.551 632 812 5 mL
|
| dram (U.S. fluid); U.S. fluidram
| fl dr
| ≡ 1/8 US fl oz = 3.696 691 195 312 5 mL
|
| teaspoon (Canadian)
| tsp
| ≡ 1/6 fl oz ≈ 4.735 510 416 667 mL
|
| teaspoon (U.S.)
| tsp
| ≡ 1/6 US fl oz = 4.928 921 595 mL
|
| teaspoon (metric)
|
| ≡ 5 mL
|
| tablespoon (Canadian)
| tbsp
| ≡ 1/2 fl oz = 14.206 531 25 mL
|
| tablespoon (U.S.)
| tbsp
| ≡ 1/2 US fl oz = 14.786 764 782 5 mL
|
| tablespoon (metric)
|
| ≡ 15 mL
|
| cubic inch
| cu in
| ≡ 1 in³ = 16.387 064 mL
|
| tablespoon (Imperial)
| tbsp
| ≡ 5/8 fl oz = 17.758 164 062 5 mL
|
| fluid ounce (Imperial)
| fl oz (Imp)
| ≡ 1/160 gal (Imp) = 28.413 062 5 mL
|
| fluid ounce (U.S.)
| fl oz (US)
| ≡ 1/128 gal (US) = 29.573 529 562 5 mL
|
| gill (U.S.)
| gi (US)
| ≡ 4 US fl oz = 118.294 118 25 mL
|
| gill (Imperial); Noggin
| gi (Imp); nog
| ≡ 5 Imp fl oz = 142.065 312 5 mL
|
| cup (Canadian)
| c (CA)
| ≡ 8 fl oz (Imp) = 227.3045 mL
|
| cup (U.S.)
| c (US)
| ≡ 1/16 gal (US) = 236.588 236 5 mL
|
| cup (Metric)
| c
| ≡ 250 mL
|
| pint (U.S. fluid)
| pt (US fl)
| ≡ 1/8 gal (US) = 473.176 473 mL
|
| pint (U.S. dry)
| pt (US dry)
| ≡ 1/4 bu (US lvl) = 550.610 471 357 5 mL
|
| pint (Imperial)
| pt (Imp)
| ≡ 1/8 gal (Imp) = 568.261 25 mL
|
| quart (U.S. fluid)
| qt (US)
| ≡ 1/4 gal (US fl) = 0.946 352 946 L
|
| quart (U.S. dry)
| qt (US)
| ≡ 1/32 bu (US lvl) = 1/4 gal (US dry) = 1.101 220 942 715 L
|
| quart (Imperial)
| qt (Imp)
| ≡ 1/4 gal (Imp) = 1.136 522 5 L
|
| board-foot
| fbm
| ≡ 144 cu in = 2.359 737 216 L
|
| gallon (U.S. fluid)
| gal (US)
| ≡ 231 cu in = 3.785 411 784 L
|
| gallon (U.S. dry)
| gal (US)
| ≡ 1/8 bu (US lvl) = 4.404 883 770 86 L
|
| gallon (Imperial)
| gal (Imp)
| ≡ 4.546 09 L
|
| peck (U.S. dry)
| pk
| ≡ 1/4 US lvl bu = 8.809 767 541 72 L
|
| peck (Imperial)
| pk
| ≡ 2 Imp gal = 9.092 18 L
|
| bucket (Imperial)
| bkt
| ≡ 4 Imp gal = 18.184 36 L
|
| timber foot
|
| ≡ 1 cu ft = 28.316 846 592 L
|
| cubic foot
| cu ft
| ≡ 1728 cu in = 28.316 846 592 L
|
| firkin
|
| ≡ 9 US gal = 34.068 706 056 L
|
| bushel (U.S. dry level)
| bu (US lvl)
| ≡ 2150.42 cu in = 35.239 070 166 88 L
|
| bushel (Imperial)
| bu (Imp)
| ≡ 8 gal (Imp) = 36.368 72 L
|
| bushel (U.S. dry heaped)
| bu (US)
| ≡ 1 1/4 bu (US lvl) = 44.048 837 708 6 L
|
| strike (U.S.)
|
| ≡ 2 bu (US lvl) = 70.478 140 333 76 L
|
| strike (Imperial)
|
| ≡ 2 bu (Imp) = 72.737 44 L
|
| kilderkin
|
| ≡ 18 gal (Imp) = 81.829 62 L
|
| sack (U.S.)
|
| ≡ 3 bu (US lvl) = 105.717 210 500 64 L
|
| sack (Imperial); Bag
|
| ≡ 3 bu (Imp) = 109.106 16 L
|
| barrel (U.S. dry)
| bl (US)
| ≡ 105 qt (US) = 105/32 bu (US lvl) = 115.628 198 985 075 L
|
| barrel (U.S. fluid)
| fl bl (US)
| ≡ 31 1/2 gal (US) = 119.240 471 196 L
|
| coomb
|
| ≡ 4 bu (Imp) = 145.474 88 L
|
| barrel (U.S. oil)
| bl
| ≡ 42 gal (US) = 158.987 294 928 L
|
| barrel (Imperial)
| bl (Imp)
| ≡ 36 gal (Imp) = 163.659 24 L
|
| hogshead (U.S.)
| hhd (US)
| ≡ 2 fl bl (US) = 163.659 24 L
|
| seam
|
| ≡ 8 bu (US lvl) = 281.912 561 335 04 L
|
| quarter; pail
|
| ≡ 8 bu (Imp) = 290.949 76 L
|
| hogshead (Imperial)
| hhd (Imp)
| ≡ 2 bl (Imp) = 327.318 48 L
|
| cord-foot
|
| ≡ 16 cu ft = 0.453 069 545 472 m³
|
| butt (U.S.)
|
| ≡ 126 gal (US) = 0.476 961 884 784 m³
|
| butt (Imperial)
|
| ≡ 126 gal (Imp) = 0.572 807 34 m³
|
| perch
| per
| ≡ 16 1/2 ft × 1 1/2 ft × 1 ft = 0.700 841 953 152 m³
|
| cubic yard
| cu yd
| ≡ 27 cu ft = 0.764 554 857 984 m³
|
| displacement ton
|
| ≡ 35 cu ft = 0.991 089 630 72 m³
|
| freight ton
|
| ≡ 40 cu ft = 1.132 673 863 68 m³
|
| tun
|
| ≡ 252 gal (Imp) = 1.145 614 68 m³
|
| chaldron (Imperial)
|
| ≡ 32 bu (Imp) = 1.163 799 04 m³
|
| chaldron (U.S.)
|
| ≡ 36 bu (US lvl) = 1.268 606 526 007 68 m³
|
| wey (U.S.)
|
| ≡ 40 bu (US lvl) = 1.409 562 806 675 2 m³
|
| load
|
| ≡ 50 cu ft = 1.415 842 329 6 m³
|
| register ton
|
| ≡ 100 cu ft = 2.831 684 659 2 m³
|
| last
|
| ≡ 80 bu (Imp) = 2.909 497 6 m³
|
| cord
|
| ≡ 8 ft × 4 ft × 4 ft = 3.624 556 363 776 m³
|
| acre-inch
|
| ≡ 1 ac × 1 in = 102.790 153 128 96 m³
|
| acre-foot
|
| ≡ 1 ac × 1 ft = 1233.481 837 547 52 m³
|
| cubic mile
| cu mi
| ≡ 1 mi³ = 4.168 181 825 440 579 584 km³
|
| Name of unit
| Symbol
| Relation to SI units
|
| Mass, m
|
| kilogram
| kg
| (SI base unit)
|
| electron rest mass
| me
| ≈ 9.109 381 88×10-31 ± 72×10-39 kg
|
| atomic unit of mass
| au
| ≡ me ≈ 9.109 381 88×10-31 ± 72×10-39 kg
|
| unified atomic mass unit
| amu
| ≈ 1.660 538 73×10-27 ± 13×10-35 kg
|
| dalton
| Da
| ≈ 1.660 902 10×10-27 ± 13×10-35 kg
|
| gamma
| γ
| ≡ 1 μg
|
| point
|
| ≡ 1/100 kt (metric) = 2 mg
|
| mite
|
| ≡ 1/20 gr = 3.239 945 5 mg
|
| mite (metric)
|
| ≡ 1/20 g = 50 mg
|
| grain
| gr
| ≡ 64.798 91 mg
|
| crith
|
| ≈ 89.9349 mg
|
| carat (metric)
| kt
| ≡ 200 mg
|
| carat
| kt
| ≡ 3 1/6 gr ≈ 205.196 548 333 mg
|
| sheet
|
| ≡ 1/700 lb av = 647.9891 mg
|
| scruple (avoirdupois)
| s av
| ≡ 20 gr = 1.295 978 2 g
|
| pennyweight
| dwt; pwt
| ≡ 1/20 oz t = 1.555 173 84 g
|
| dram (avoirdupois)
| dr av
| ≡ 27 11/32 gr = 1.771 845 195 312 5 g
|
| dram (apothecary; troy)
| dr t
| ≡ 60 gr = 3.887 934 6 g
|
| hyl (CGS unit)
|
| ≡ 1 gee × 1 g × 1 s²/m = 9.806 65 g
|
| ounce (avoirdupois)
| oz av
| ≡ 1/16 lb = 28.349 523 125 g
|
| assay ton (short)
| AT
| ≡ 1 mg × 1 sh tn ÷ 1 oz t ≈ 29.166 667 g
|
| ounce (apothecary; troy)
| oz t
| ≡ 31.103 476 8 g
|
| assay ton (long)
| AT
| ≡ 1 mg × 1 long tn ÷ 1 oz t ≈ 32.666 667 g
|
| mark
|
| ≡ 8 oz t = 248.827 814 4 g
|
| pound (troy)
| lb t
| ≡ 5760 grains = 0.373 241 721 6 kg
|
| pound (avoirdupois)
| lb av
| ≡ 7000 grains = 0.453 592 37 kg
|
| pound (metric)
|
| ≡ 500 g
|
| clove
|
| ≡ 8 lb av = 3.628 738 96 kg
|
| stone
| st
| ≡ 14 lb av = 6.350 293 18 kg
|
| hyl (MKSA unit)
|
| ≡ 1 gee × 1 kg × 1 s²/m = 9.806 65 kg
|
| quarter (Imperial)
|
| ≡ 1/4 long cwt = 2 st = 28 lb av = 12.700 586 36 kg
|
| slug; geepound
| slug
| ≡ 1 gee × 1 lb av × 1 s²/ft ≈ 14.593 903 kg
|
| bag
|
| ≡ 94 lb av = 42.637 682 78 kg
|
| short hundredweight; cental
| sh cwt
| ≡ 100 lb av = 45.359 237 kg
|
| long hundredweight (U.S.) or hundredweight (Imperial)
| long cwt or cwt
| ≡ 112 lb av = 50.802 345 44 kg
|
| quintal (metric)
|
| ≡ 100 kg
|
| wey
|
| ≡ 252 lb = 18 st = 114.305 277 24 kg (variants exist)
|
| short quarter (U.S.)
|
| ≡ 1/4 sh tn = 226.796 185 kg
|
| long quarter (U.S.)
|
| ≡ 1/4 long tn = 254.011 727 2 kg
|
| kip
| kip
| ≡ 1000 lb av = 453.592 37 kg
|
| short ton
| sh tn
| ≡ 2000 lb = 907.184 74 kg
|
| tonne (mts unit)
| t
| ≡ 1000 kg
|
| long ton (U.S.) or ton (Imperial)
| long tn or ton
| ≡ 2240 lb = 1016.046 908 8 kg
|
| barge
|
| ≡ 22 1/2 sh tn = 20,411.656 65 kg
|
| Name of unit
| Symbol
| Relation to SI units
|
| Time, t
|
| second
| s
| (SI base unit)
|
| Planck time
|
| ≡ √Gh/c5 ≈ 1.351 211 818×10-43 s
|
| atomic unit of time
| au
| ≡ a0/(α·c) ≈ 2.418 884 254×10-17 s
|
| svedberg
| S
| ≡ 10-13 s = 100 fs
|
| shake
|
| ≡ 10-8 s = 10 ns
|
| sigma
|
| ≡ 10-6 s = 1 μs
|
| jiffy
|
| ≡ 1/60 s ≈ 16.666 667 ms (sometimes ≡ 1/100 s = 10 ms)
|
| minute
| min
| ≡ 60 s
|
| hour
| h
| ≡ 60 min = 3600 s
|
| day
| d
| ≡ 24 h = 86 400 s
|
| week
| wk
| ≡ 7 d = 604 800 s
|
| fortnight
|
| ≡ 2 wk = 1 209 600 s
|
| month (hollow)
| mo
| ≡ 29 d = 2 505 600 s
|
| month (full)
| mo
| ≡ 30 d = 2 592 000 s
|
| year (Calendar)
| a
| ≡ 365 d = 31 536 000 s
|
| year (Gregorian)
| a
| ≡ 365.2425 d = 31 556 952 s
|
| year (Julian)
| a
| ≡ 365.25 d = 31 557 600 s
|
| lustre; lustrum
|
| ≡ 5 a of 365 d = 1.5768×108 s
|
| octaeteris
|
| ≡ 8 a of 365 d = 2.522 88×108 s
|
| decade
|
| ≡ 10 a of 365 d = 3.1536×108 s
|
| enneadecaeteris; Metonic cycle
|
| ≡ 110 mo (hollow) + 125 mo (full) = 19 a of 365 d = 5.996 16×108 s
|
| Callippic cycle
|
| ≡ 441 mo (hollow) + 499 mo (full) = 76 a of 365.25 d = 2.398 377 6×109 s
|
| century (Calendar)
|
| ≡ 100 a of 365 d = 3.1536×109 s
|
| century (Julian)
|
| ≡ 100 a of 365.25 d = 3.155 76×109 s
|
| Hipparchic cycle
|
| ≡ 4 Callippic cycles - 1 d = 9.593 424×109 s
|
| millennium (Calendar)
|
| ≡ 1000 a of 365 d = 3.1536×1010 s
|
| millennium (Gregorian)
|
| ≡ 1000 a of 365.2425 d = 3.155 695 2×1010 s
|
| millennium (Julian)
|
| ≡ 1000 a of 365.25 d = 3.155 76×1010 s
|
| Sothic cycle
|
| ≡ 1461 a of 365 d = 4.607 409 6×1010 s
|
| Name of unit
| Symbol
| Relation to SI units
|
| Pressure, P
|
| pascal (SI unit)
| Pa
| ≡ N/m² = kg/m·s²
|
| barye (cgs unit)
|
| ≡ 1 dyn/cm² = 0.1 Pa
|
| poundal per square foot
| pdl/sq ft
| ≡ 1 pdl/sq ft ≈ 1.488 164 Pa
|
| millimetre of water (4°C)
| mmH2O
| ≡ 1000 kg/m³ × 1 mm × g = 9.806 65 Pa (= 1 kgf/m²)
|
| pound per square foot
| psf
| ≡ 1 lb/sq ft × g ≈ 47.880 259 Pa
|
| centimetre of water (4°C)
| cmH2O
| ≡ 1000 kg/m³ × 1 cm × g = 98.0665 Pa
|
| torr
| torr
| ≡ (101 325/760) Pa ≈ 133.322 Pa
|
| millimetre of mercury
| mmHg
| ≡ 13 595.1 kg/m³ × 1 mm × g = 133.322 387 415 Pa (≈ 1 torr)
|
| inch of water (4°C)
| inH2O
| ≡ 1000 kg/m³ × 1 in × g = 249.088 91 Pa
|
| pièze (mts unit)
| pz
| ≡ 1000 kg/m·s² = 1 kPa
|
| centimetre of mercury
| cmHg
| ≡ 13 595.1 kg/m³ × 1 cm × g = 1.333 223 874 15 kPa (≈ 10 torr)
|
| foot of water (4°C)
| ftH2O
| ≡ 1000 kg/m³ × 1 ft × g = 2.989 066 92 kPa
|
| inch of mercury
| inHg
| ≡ 13 595.1 kg/m³ × 1 in × g = 3.386 388 640 341 kPa
|
| pound per square inch
| psi
| ≡ 1 lb × g / 1 sq in ≈ 6.894 757×103 Pa
|
| foot of mercury
| ftHg
| ≡ 13 595.1 kg/m³ × 1 ft × g = 40.636 663 684 091 9 kPa
|
| ton per square foot
|
| ≡ 1 sh tn × g / 1 sq ft ≈ 95.760 518 kPa
|
| atmosphere (technical)
| atm
| ≡ 1 kgf/cm² = 98.0665 kPa
|
| bar
| bar
| ≡ 105 Pa
|
| atmosphere (standard)
| atm
| ≡ 101 325 Pa
|
| kip per square inch
| ksi
| ≡ 1 kipf/sq in ≈ 6.894757 MPa
|
| kilogram-force per square millimetre
| kgf/mm²
| ≡ 1 kgf/mm² = 9.806 65 MPa
|
| Name of unit
| Symbol
| Relation to SI units
|
| Energy, E
|
| joule (SI unit)
| J
| ≡ N·m = kg·m²/s²
|
| electronvolt
| eV
| ≡ e × 1 V = 1/6.241 509 629 152 65×1018 J ≈ 1.602 176×10-19 J
|
| rydberg
| Ry
| ≡ R∞·h·c ≈ 2.179 872×10-18 J
|
| hartree
| Eh
| ≡ me·α²·c² ≈ 4.359 744×10-18 J (= 2Ry)
|
| atomic unit of energy
| au
| ≡ Eh ≈ 4.359 744×10-18 J |
| erg (cgs unit)
| erg
| ≡ 1 g·cm²/s² = 10-7 J
|
| foot-poundal
| ft pdl
| ≡ 1 ft·pdl = 4.214 011 009 380 48×10-2 J
|
| cubic centimetre of atmosphere; standard cubic centimetre
| cc atm; scc
| ≡ 1 atm × 1 cm³ = 0.101 325 J
|
| inch-pound force
| in lbf
| ≡ g × 1 lb × 1 in = 0.112 984 829 027 616 7 J
|
| foot-pound force
| ft lbf
| ≡ g × 1 lb × 1 ft = 1.355 817 948 331 400 4 J
|
| calorie (20°C)
| cal20°C
| ≈ 4.1819 J
|
| calorie (thermochemical)
| calth
| ≡ 4.184 J
|
| calorie (15°C)
| cal15°C
| ≡ 4.1855 J
|
| calorie (International Table)
| calIT
| ≡ 4.1868 J
|
| calorie (mean)
| calmean
| ≈ 4.190 02 J
|
| calorie (4°C)
| cal4°C
| ≈ 4.2045 J
|
| litre of atmosphere; standard litre
| l atm; sl
| ≡ 1 atm × 1 L = 101.325 J
|
| gallon of atmosphere (U.S.)
| gal atm
| ≡ 1 atm × 1 gal (US) = 383.556 849 013 8 J
|
| gallon of atmosphere (Imperial)
| gal atm
| ≡ 1 atm × 1 gal (Imp) = 460.632 569 25 J
|
| British thermal unit (thermochemical)
| BTUth
| ≡ 1 lb/g × 1 calth × 1 °F/°C = 9.489 152 380 4 ÷ 9 kJ ≈ 1.054 350 kJ
|
| British thermal unit (ISO)
| BTUISO
| ≡ 1.0545 kJ
|
| British thermal unit (63°F)
| BTU63°F
| ≈ 1.0546 kJ
|
| British thermal unit (60°F)
| BTU60°F
| ≈ 1.054 68 kJ
|
| British thermal unit (59°F)
| BTU59°F
| ≡ 1.054 804 kJ
|
| British thermal unit (International Table)
| BTUIT
| ≡ 1 lb/g × 1 calIT × 1 °F/°C = 1.055 055 852 62 kJ
|
| British thermal unit (mean)
| BTUmean
| ≈ 1.055 87 kJ
|
| British thermal unit (39°F)
| BTU39°F
| ≈ 1.059 67 kJ
|
| Celsius heat unit (International Table)
| CHUIT
| ≡ 1 BTUIT × 1 °C/°F = 1.899 100 534 716 kJ
|
| cubic foot of atmosphere; standard cubic foot
| cu ft atm; scf
| ≡ 1 atm × 1 cu ft = 2.869 204 480 934 4 kJ
|
| kilocalorie; large calorie
| kcal; Cal
| ≡ 1000 calIT = 4.1868 kJ
|
| cubic yard of atmosphere; standard cubic yard
| cu yd atm; scy
| ≡ 1 atm × 1 cu yd = 77.468 520 985 228 8 kJ
|
| cubic foot of natural gas
|
| ≡ 1000 BTUIT = 1.055 055 852 62 MJ
|
| horsepower-hour
| hph
| ≡ 1 hp (electrical imperial) × 1 h = 2.6856 MJ
|
| Board of Trade Unit; kilowatt-hour
| B.O.T.U.; kWh
| ≡ 1 kW × 1 h = 3.6 MJ
|
| thermie
| th
| ≡ 1 McalIT = 4.1868 MJ
|
| therm (U.S.)
|
| ≡ 100 000 BTU59°F = 105.4804 MJ
|
| therm (E.C.)
|
| ≡ 100 000 BTUIT = 105.505 585 262 MJ
|
| ton of TNT
| tTNT
| ≡ 1 Gcalth = 4.184 GJ
|
| barrel of oil equivalent
| bboe
| ≈ 5.8 MBTU59°F ≈ 6.12 GJ
|
| ton of coal equivalent
| TCE
| ≡ 7 Gcalth = 29.3076 GJ
|
| ton of oil equivalent
| TOE
| ≡ 10 Gcalth = 41.868 GJ
|
| quad
|
| ≡ 1015 BTUIT = 1.055 055 852 62 EJ
|
| Name of unit
| Symbol
| Relation to SI units
|
| Power, P
|
| watt (SI unit)
| W
| ≡ J/s = N·m/s = kg·m²/s³
|
| lusec
| lusec
| ≡ 1 L-µmHg/s ≈ 1.333 224×10-4 W
|
| foot-pound-force per hour
| ft lbf/h
| ≡ 1 ft lbf/h ≈ 3.766 161×10-4 W
|
| standard cubic centimetre per minute
| sccm
| ≡ 1 atm cm³/min = 1.688 75×10-3 W
|
| foot-pound-force per minute
| ft lbf/min
| ≡ 1 ft lbf/min = 2.259 696 580 552 334×10-2 W
|
| standard cubic centimetre per second
| sccs
| ≡ 1 atm cm³/s = 0.101 325 W
|
| BTU (International Table) per hour
| BTUIT/h
| ≡ 1 BTUIT/h ≈ 0.293 071 W
|
| standard cubic foot per hour
| scfh
| ≡ 1 atm cu ft/h = 0.797 001 244 704 W
|
| foot-pound-force per second
| ft lbf/s
| ≡ 1 ft lbf/s = 1.355 817 948 331 400 4 W
|
| standard litre per minute
| slpm
| ≡ 1 atm L/min = 1.688 75 W
|
| calorie (International Table) per second
| calIT/s
| ≡ 1 calIT/s = 4.1868 W
|
| BTU (International Table) per minute
| BTUIT/min
| ≡ 1 BTUIT/min ≈ 17.584 264 W
|
| standard cubic foot per minute
| scfm
| ≡ 1 atm cu ft/min = 47.820 074 682 24 W
|
| square foot equivalent direct radiation
| sq ft EDR
| ≡ 240 BTUIT/h ≈ 70.337 057 W
|
| standard litre per second
| slps
| ≡ 1 atm L/s = 101.325 W
|
| horsepower (metric)
| hp
| ≡ 75 m kgf/s = 735.498 75 W
|
| horsepower (U.S.)
| hp (US)
| ≈ 735.7 W
|
| horsepower (European electrical)
| hp
| ≡ 736 W
|
| horsepower (Imperial mechanical)
| hp
| ≡ 550 ft lbf/s = 745.699 871 582 270 22 W
|
| horsepower (Imperial electrical)
| hp
| ≡ 746 W
|
| horsepower (water)
| hp (US)
| ≈ 746.043 W
|
| ton of air conditioning
|
| ≡ 1 t × 1005 J/kg × 1 °F/K ÷ 10 min = 844.2 W
|
| poncelet
| p
| ≡ 100 m kgf/s = 980.665 W
|
| BTU (International Table) per second
| BTUIT/s
| ≡ 1 BTUIT/s = 1.055 055 852 62×10+3 W
|
| standard cubic foot per second
| scfs
| ≡ 1 atm cu ft/s = 2.869 204 480 934 4×10+3 W
|
| ton of refrigeration (IT)
|
| ≡ 1 BTUIT × 1 sh tn/lb ÷ 10 min/s ≈ 3.516 853×10+3 W
|
| ton of refrigeration (Imperial)
|
| ≡ 1 BTUIT × 1 lng tn/lb ÷ 10 min/s ≈ 3.938 875×10+3 W
|
| boiler horsepower
| bhp
| ≈ 34.5 lb/h × 970.3 BTUIT/lb ≈ 9.810 657×10+3 W
|
