120 knots to miles per hour
138.09 mph
120 kn = 138.09 mph.
miles per hour
138.09mph
120 kn = 138.09 mph
In short
How many miles per hour is 120 knots?
120 kn = 138.09 mph. 1 knot = 1.150779 miles per hour, so the working is 120 × 1.150779 = 138.09.
The working
The factor below is an exact definition rather than a measurement, so nothing is approximated in the arithmetic. The only rounding on this page happens where a number is displayed.
1 knot = 1.150779 miles per hour 120 × 1.150779 = 138.09
How much precision do you need?
Each row is the same answer cut at a different number of decimals, with what that choice costs you. Pick the shortest row whose error is smaller than whatever you are measuring with.
| Rounded to | Answer (mph) | Off by |
|---|---|---|
| Whole number | 138 | −0.09353 |
| 1 decimal | 138.1 | +0.00647 |
| 2 decimals | 138.09 | −0.00353 |
Round trip: take 138.09 mph back the other way and you land on 119.9969 kn — a drift of 0.0031 kn. That gap is the rounding, not the conversion.
Frequently asked questions
What is 120 knots in miles per hour?
120 knots is 138.09 miles per hour. 1 knot = 1.150779 miles per hour, so the working is 120 × 1.150779 = 138.09.
How accurate is 138.09 mph?
Rounding to 138.09 mph and converting straight back gives 119.9969 kn, a drift of 0.0031 kn from the 120 you started with. The factor itself is exact; every bit of that difference comes from the rounding, not the conversion.
Nearby values
Any value at all
Knots to MPH Converter
Convert knots to miles per hour — boat speed, wind speed, and aviation.
Open the knots to MPH converter →