Femtometer is 1e-15 meter units.
Femtometers to Chains Converter — fm to ch
Convert Femtometer (fm) to Chain (ch) using the exact conversion factor (1 femtometer = 4.97097e-17 chain). See the formula, worked examples, and conversion table.
Femtometers to Chains converter
Converter
Length Converter
Convert SI, imperial, US customary, astronomical, scientific, and historical length units.
Context values
Some unit families need one extra value for a physically accurate result.
A surveyor's chain is 66 feet.
Result = input x 1e-15 / 20.1168.
Length uses the meter as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Femtometers to Chains
Femtometer and Chain both measure length. Specifically: Femtometer is 1e-15 meter units, and a surveyor's chain is 66 feet.
Formula
chains = femtometers × 4.97097e-17
This factor comes from each unit's defined relationship to the category's base unit: 1 femtometer equals 1e-15 base units, and 1 chain equals 20.1168 base units, so dividing one by the other gives the direct femtometer-to-chain factor of 4.97097e-17.
Simple example
1 fm × 4.97097e-17 = 4.97097e-17 ch
1 femtometer = 4.97097e-17 chains.
Real-world example
10 fm × 4.97097e-17 = 4.97097e-16 ch
10 femtometers = 4.97097e-16 chains.
Conversion table
| Femtometer (fm) | Chain (ch) |
|---|---|
| 1 fm | 4.97097e-17 ch |
| 5 fm | 2.485485e-16 ch |
| 10 fm | 4.97097e-16 ch |
| 21.0975 fm | 1.04875e-15 ch |
| 42.195 fm | 2.097501e-15 ch |
| 100 fm | 4.97097e-15 ch |
Reverse conversion: Chain to Femtometer
4.97097e-17 ch × 2.01168e+16 = 1.000000093 fm
4.97097e-17 chains = 1.000000093 femtometers.
femtometers = chains × 2.01168e+16
For a page dedicated to this direction, see Chain to Femtometer.
Understanding the Femtometer (fm)
Femtometer is 1e-15 meter units.
Understanding the Chain (ch)
A surveyor's chain is 66 feet.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many chains are in 1 femtometer?
1 femtometer equals 4.97097e-17 chains, using the exact defined conversion factor rather than an estimate.
How do I convert femtometer to chain?
Multiply the femtometer value by 4.97097e-17. The converter above does this instantly to whatever precision you set.
How do I convert chain back to femtometer?
Use the reverse factor: 1 chain equals 2.01168e+16 femtometers. You can also use the swap control in the converter above to flip the direction instantly.
What is a femtometer?
Femtometer (fm) is a unit of length.
What is a chain?
Chain (ch) is a unit of length.
Is the femtometer to chain conversion exact?
Yes. Both femtometer and chain are defined by fixed standards rather than physical artifacts, so the factor of 4.97097e-17 used above is exact to as many digits as you choose to display.