Convert British thermal unit to calorie
1 BTU = 252.1644007 cal
1 BTU = 252.16 cal
1 BTU in every energy unit
| electron volt | 6.5851e+21 eV |
| hartree | 2.4200e+20 Eh |
| kiloelectron volt | 6.5851e+18 keV |
| megaelectron volt | 6.5851e+15 MeV |
| gigaelectron volt | 6,585,100,000,000 GeV |
| nanojoule | 1,055,100,000,000 nJ |
| erg | 10,551,000,000 erg |
| teraelectron volt | 6,585,100,000 TeV |
| microjoule | 1,055,100,000 µJ |
| millijoule | 1,055,100 mJ |
| inch-pound | 9,338 in·lb |
| joule | 1,055.1 J |
| foot-pound | 778.17 ft⋅lb |
| calorie | 252.16 cal |
| calorie (International Table) | 252 cal IT |
| kilojoule | 1.0551 kJ |
| BTU (thermochemical) | 1.0007 BTU th |
| British thermal unit | 1 BTU |
| watt-hour | 0.29307 Wh |
| kilocalorie | 0.25216 kcal |
| megajoule | 0.0010551 MJ |
| horsepower-hour | 0.00039301 hp·h |
| kilowatt-hour | 0.00029307 kWh |
| therm | 0.00001 therm |
| gigajoule | 0.0000010551 GJ |
| million BTU | 0.000001 MMBTU |
| megawatt-hour | 2.9307e-07 MWh |
| ton of TNT | 2.5216e-07 t TNT |
| tonne of oil equivalent | 2.5200e-08 toe |
| terajoule | 1.0551e-09 TJ |
| gigawatt-hour | 2.9307e-10 GWh |
| kiloton of TNT | 2.5216e-10 kt TNT |
| petajoule | 1.0551e-12 PJ |
| terawatt-hour | 2.9307e-13 TWh |
| megaton of TNT | 2.5216e-13 Mt TNT |
| quad | 1.0000e-15 quad |
How the conversion works
Multiply by 252.1644007 to go from British thermal unit to calorie, or divide by it to go back. Every conversion on this site routes through the SI value (J) rather than a table of pairwise factors, so a round-trip returns exactly what you started with.
Going the other way? calorie to British thermal unit — 1 cal = 0.003965666831 BTU.
British thermal unit to calorie — common values
| 1 BTU | 252.1644 cal |
| 2 BTU | 504.3288 cal |
| 3 BTU | 756.4932 cal |
| 5 BTU | 1,260.822 cal |
| 10 BTU | 2,521.644 cal |
| 15 BTU | 3,782.466 cal |
| 20 BTU | 5,043.288 cal |
| 25 BTU | 6,304.11 cal |
| 50 BTU | 12,608.22 cal |
| 75 BTU | 18,912.33 cal |
| 100 BTU | 25,216.44 cal |
| 250 BTU | 63,041.1 cal |
| 500 BTU | 126,082.2 cal |
| 1000 BTU | 252,164.4 cal |