mph to km/h Converter

Convert speed between mph to km/h instantly. It’s handy when you’re reading car specs, checking treadmill or cycling data, crossing borders with different speed limits, or comparing GPS readouts that use another unit.

The mph to km/h Converter lets you type a value in either unit and get a precise counterpart right away. The goal is quick, error-free conversions so you can log workouts consistently, plan travel times accurately, and comply with local signage—no manual math or guesswork needed.

Speed conversion for running, cycling, and driving—live as you type, with pace equivalents and a copy-link.

Type mph or km/h to convert instantly. Pace shown for running and cycling.

Enter a speed

Miles per hour

mph

Kilometers per hour

km/h

Rounding

Enter either mph or km/h—results update instantly. We also show pace equivalents for training: minutes per mile and minutes per kilometer.

mph to km/h Results

mph

km/h

9.66

Pace (per mile)

10:00 / mile

Pace (per km)

6:13 / km

We compute at full precision and round only for display.

Pace is the reciprocal of speed (minutes per unit).

Common speeds & pace

mph	km/h	Pace / mile	Pace / km
3	4.83	20:00 / mile	12:26 / km
4	6.44	15:00 / mile	9:19 / km
5	8.05	12:00 / mile	7:27 / km
6	9.66	10:00 / mile	6:13 / km
7.5	12.07	8:00 / mile	4:58 / km
10	16.09	6:00 / mile	3:44 / km
12	19.31	5:00 / mile	3:06 / km
15	24.14	4:00 / mile	2:29 / km

Results interpretation

Training context: pace translates a speed target into time per mile or per kilometer—useful for intervals and long runs.
Rounding: adjust decimals for display; we keep full-precision math internally.
Cycling & driving: prefer km/h where signage or bike computers default to metric.

How mph ↔ km/h conversion works

Formulas, steps, and assumptions

Formulas: km/h = mph × 1.609344; mph = km/h ÷ 1.609344 (exact constants).

Pace: pace_mile = 60 ÷ mph; pace_km = 60 ÷ km/h.

Steps: enter either side → adjust rounding → review pace equivalents → copy a link with your inputs.

Assumptions: steady speed; no grade or wind adjustments.

Limitations: real-world pace fluctuates; treat these as planning baselines.

Use cases & examples

Example 1 (running): 6.5 mph → 10.46 km/h. Pace ≈ 9:13 per mile, 5:44 per km.

Example 2 (cycling): 30 km/h → 18.64 mph. Pace ≈ 3:13 per km, 5:10 per mile.

Example 3 (driving): 70 mph speed limit ≈ 112.65 km/h.

mph to km/h — FAQ

How do I convert mph to km/h?

Multiply mph by 1.609344. Example: 10 mph × 1.609344 = 16.09344 km/h.

How do I convert km/h to mph?

Divide km/h by 1.609344 (or multiply by 0.621371192).

How do you calculate running pace from speed?

Pace per mile is 60 ÷ mph; pace per kilometer is 60 ÷ km/h.

Why do my pace numbers change when I switch units?

Pace is minutes per unit; when the unit changes (mile vs. kilometer), the value changes accordingly.

What rounding should I use?

Choose the number of decimals that matches your watch or reporting needs—1–2 decimals are common.

Is the conversion factor exact?

Yes. 1 mile = 1.609344 kilometers exactly, so the factor is exact.

Speed, pace, and practical targets

We convert between mph and km/h using exact constants so training plans and trip estimates stay consistent. Pace values turn a speed goal into time splits, which is how many runners and cyclists structure workouts.

Why pace matters

Speed feels abstract on foot; pace answers “how long per mile or per kilometer?” This framing helps calibrate effort across terrains and conditions.

Rounding for readability

We keep full precision for math and only round what you see. If your watch shows tenths, set decimals to 1–2 to match.

Common checkpoints

Recreational running often ranges 4–7 mph (6.4–11.3 km/h). Club rides cluster around 25–32 km/h (15.5–19.9 mph) on flats.