Home › Unit Conversion › Foot-pounds to Joules
Foot-pounds to Joules (ft·lbf to J)
Convert foot-pounds to joules: 1 ft·lbf = 1.35582 J. Exact conversion factor, formula, 22-row table and worked examples, with JSON API and MCP access.
Formula
1 ft·lbf = 1.35582 J
joules = foot-pounds × 1.355817948 — reverse: foot-pounds = joules × 0.7375621493
The factor is derived from the SI definitions of both units (base unit: J) as listed in NIST SP 811; results on this page are shown to 6 significant figures, the API returns up to 12.
Worked examples
- 5 ft·lbf = 6.77909 J
- 12.5 ft·lbf = 16.9477 J
- 100 ft·lbf = 135.582 J
Foot-pounds to joules conversion table
| Foot-pounds (ft·lbf) | Joules (J) |
|---|---|
| 1 | 1.35582 |
| 2 | 2.71164 |
| 3 | 4.06745 |
| 4 | 5.42327 |
| 5 | 6.77909 |
| 6 | 8.13491 |
| 7 | 9.49073 |
| 8 | 10.8465 |
| 9 | 12.2024 |
| 10 | 13.5582 |
| 15 | 20.3373 |
| 20 | 27.1164 |
| 25 | 33.8954 |
| 30 | 40.6745 |
| 40 | 54.2327 |
| 50 | 67.7909 |
| 75 | 101.686 |
| 100 | 135.582 |
| 200 | 271.164 |
| 250 | 338.954 |
| 500 | 677.909 |
| 1000 | 1355.82 |
FAQ
How many joules are in one foot-pound?
1 ft·lbf = 1.35582 J. The factor comes from the SI definitions of both units (NIST SP 811 / BIPM), so it is exact or correct to at least 10 significant figures.
What is the formula to convert foot-pounds to joules?
Multiply the value in foot-pounds by 1.355817948: joules = foot-pounds × 1.355817948. For example, 5 ft·lbf = 6.77909 J.
How do I convert joules back to foot-pounds?
Multiply by the inverse factor 0.7375621493 (foot-pounds = joules × 0.7375621493), or use the joules-to-foot-pounds page.
Related conversions
- Joules to foot-pounds (reverse)
- Energy Converter — all energy units in one tool
- Kilocalories (food calories) to Kilojoules
- Kilojoules to Kilocalories (food calories)
- Joules to Calories (small, thermochemical)
- Calories (small, thermochemical) to Joules
- Kilowatt-hours to Megajoules
- Megajoules to Kilowatt-hours
- Kilowatt-hours to BTU
- BTU to Kilowatt-hours
Machine access
- API:
GET https://tttkmbb.com/api/v1/convert?value=5&from_unit=ft_lbf&to_unit=J - MCP: server
https://tttkmbb.com/mcp, toolconvert_unitswith{"value":5,"from_unit":"ft_lbf","to_unit":"J"} - Markdown: https://tttkmbb.com/conversion/foot-pounds-to-joules.md · JSON: https://tttkmbb.com/conversion/foot-pounds-to-joules.json (add
?value=for a result) · Units: /api/v1/units?quantity=energy - OpenAPI operationId:
convert_units. Freshness:static. Authentication: none.