Work from one pound-force over one foot.
Foot-pounds to Zeptojoules Converter — ft-lb to zJ
Convert Foot-pound (ft-lb) to Zeptojoule (zJ) using the exact conversion factor (1 foot-pound = 1.355818e+21 zeptojoule). See the formula, worked examples, and conversion table.
Foot-pounds to Zeptojoules converter
Converter
Energy Converter
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Context values
Some unit families need one extra value for a physically accurate result.
Zeptojoule is 1e-21 joule units.
Result = input x 1.355817948 / 1e-21.
Energy uses the joule as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Foot-pounds to Zeptojoules
Foot-pound and Zeptojoule both measure energy, and the conversion is especially useful for comparing nutrition labels (kilocalories) against scientific energy figures (joules). Specifically: Work from one pound-force over one foot, and zeptojoule is 1e-21 joule units.
Formula
zeptojoules = foot-pounds × 1.355818e+21
This factor comes from each unit's defined relationship to the category's base unit: 1 foot-pound equals 1.35581794833 base units, and 1 zeptojoule equals 1e-21 base units, so dividing one by the other gives the direct foot-pound-to-zeptojoule factor of 1.355818e+21.
Simple example
1 ft-lb × 1.355818e+21 = 1.355818e+21 zJ
1 foot-pound = 1.355818e+21 zeptojoules.
Real-world example
100 ft-lb × 1.355818e+21 = 1.355818e+23 zJ
100 foot-pounds = 1.355818e+23 zeptojoules.
Conversion table
| Foot-pound (ft-lb) | Zeptojoule (zJ) |
|---|---|
| 1 ft-lb | 1.355818e+21 zJ |
| 10 ft-lb | 1.355818e+22 zJ |
| 100 ft-lb | 1.355818e+23 zJ |
| 500 ft-lb | 6.77909e+23 zJ |
| 1,000 ft-lb | 1.355818e+24 zJ |
| 2,000 ft-lb | 2.711636e+24 zJ |
Reverse conversion: Zeptojoule to Foot-pound
1.355818e+21 zJ × 7.375621e-22 = 1.000000038 ft-lb
1.355818e+21 zeptojoules = 1.000000038 foot-pounds.
foot-pounds = zeptojoules × 7.375621e-22
For a page dedicated to this direction, see Zeptojoule to Foot-pound.
Understanding the Foot-pound (ft-lb)
Work from one pound-force over one foot.
Understanding the Zeptojoule (zJ)
Zeptojoule is 1e-21 joule units.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many zeptojoules are in 1 foot-pound?
1 foot-pound equals 1.355818e+21 zeptojoules, using the exact defined conversion factor rather than an estimate.
How do I convert foot-pound to zeptojoule?
Multiply the foot-pound value by 1.355818e+21. The converter above does this instantly to whatever precision you set.
How do I convert zeptojoule back to foot-pound?
Use the reverse factor: 1 zeptojoule equals 7.375621e-22 foot-pounds. You can also use the swap control in the converter above to flip the direction instantly.
What is a foot-pound?
Foot-pound (ft-lb) is a unit of energy.
What is a zeptojoule?
Zeptojoule (zJ) is a unit of energy.
Is the foot-pound to zeptojoule conversion exact?
Yes. Both foot-pound and zeptojoule are defined by fixed standards rather than physical artifacts, so the factor of 1.355818e+21 used above is exact to as many digits as you choose to display.