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Convert Calc

BTU (IT) to Foot-Pounds (ft·lbf) Converter

Enter a value to instantly convert between energy units.

Precision4 dp

1 BTU (IT) = 778.1693 Foot-Pound Force

Key Formulas

Kilocalorie → Kilojoule

kJ = kcal × 4.184

Kilojoule → Kilocalorie

kcal = kJ × 0.239006

Kilowatt-Hour → Joule

J = kWh × 3600000

Joule → Kilowatt-Hour

kWh = J × 2.77778e-7

Formula

ft·lbf = BTU × 778.169

The foot-pound and BTU are both imperial mechanical energy units, related through the mechanical equivalent of heat. Since 1 BTU = 778.17 ft·lbf exactly (from 1 lb × 1 ft × 1 °F raise per pound per degree), this conversion is precise. Mechanical engineers compare pump work, elevator energy, or motor output using these units.

Source: NIST SP 811, Table B.8

Frequently Asked Questions

Real-World Examples

A mechanical engineer checking: 1 BTU = 778 ft·lbf for a textbook example.

1 BTU = 778.17 ft·lbf

An elevator designer calculating 10 BTU motor heat dissipation in ft·lbf work equivalent.

10 BTU = 7781.7 ft·lbf

A pump engineer converting 100 BTU hydraulic work to foot-pounds for system documentation.

100 BTU = 77817 ft·lbf

A HVAC contractor estimating 1000 BTU fan energy in ft·lbf for a mechanical room layout.

1000 BTU = 778169 ft·lbf