Fathoms to Kilometers
Type a value in either box to convert between fathoms and kilometers. The factor is 0.0018288.
| Fathoms | Kilometers |
|---|---|
| 1 ftm | 0.001829 km |
| 2 ftm | 0.003658 km |
| 3 ftm | 0.005486 km |
| 5 ftm | 0.009144 km |
| 10 ftm | 0.018288 km |
| 25 ftm | 0.04572 km |
| 50 ftm | 0.09144 km |
| 100 ftm | 0.18288 km |
How to use
- Enter a value in the Fathoms field.
- The Kilometers figure appears immediately — no button to press.
- Typing in the Kilometers field converts back to Fathoms the same way.
- Use the reference table for the values that come up most often.
Fathoms to Kilometers formula
The factor from fathoms to kilometers is 0.0018288.
km = ftm × 0.0018288
Why this factor: the fathom and the kilometer are both defined against the meter, so dividing one definition by the other gives 0.0018288 directly. Both definitions are set out in full below.
To go the other way, divide by 0.0018288 — or use the Kilometers to Fathoms converter, which is the same calculation reversed.
Worked example
Start with 5 ftm. Multiply by 0.0018288 to get 0.009144 km.
5 ftm × 0.0018288 = 0.009144 km
The converter above does this for any value you type, in either direction.
What is a fathom?
A fathom is six feet, the traditional unit for water depth.
Definition: Six international feet, so exactly 1.8288 meters.
Where it is used: Nautical charts, depth soundings, and anchor and cable lengths.
What is a kilometer?
A kilometer is 1,000 meters, the standard unit for road distances and geography in most of the world.
Definition: Exactly 1,000 meters by SI prefix definition — 'kilo' means 10³.
Where it is used: Road signs, running and cycling distances, and map scales outside the US and UK.
Fathoms vs Kilometers
The fathom is a specialized unit while the kilometer is a metric unit. That is why the factor between them is not a round number: the two systems were defined independently and only later tied together by exact agreement.
Frequently asked questions
How many kilometers are in a fathom?
One fathom equals 0.0018288 kilometers.
What is the formula to convert fathoms to kilometers?
Multiply the number of fathoms by 0.0018288. To reverse it, divide by 0.0018288 instead.
How do I convert kilometers back to fathoms?
Divide by 0.0018288, which is the same as multiplying by 546.806649.
How many kilometers are in 10 fathoms?
10 ftm works out to 0.018288 km.
How is the fathom defined?
Six international feet, so exactly 1.8288 meters.