mph to m/s: 1 mph = 0.44704 m/s (exact)

The formula

m/s = mph × 0.44704

Where the factor comes from — each unit by its definition, then its size in SI:

1 mph = mi / h = 0.44704 m/s
1 m/s is the SI unit of speed.

Dividing the two SI sizes gives the factor: 0.44704, exact — every step above is a definition, not a measurement. The reverse factor is 2.23693629205.

Kinematics and energy formulas need speed in metres per second. Road speeds come in km/h or mph, so convert before you square anything: kinetic energy goes with v², so a unit slip is squared too.

Worked examples

Motorway driving (100 km/h): 62.1371 mph = 27.7778 m/s — 62.1371 × 0.44704 = 27.7778
A brisk walk (5 km/h): 3.10686 mph = 1.38889 m/s — 3.10686 × 0.44704 = 1.38889
US highway driving: 60 mph = 26.8224 m/s — 60 × 0.44704 = 26.8224
A hard-thrown ball: 67.1081 mph = 30 m/s — 67.1081 × 0.44704 = 30

Frequently asked questions

How many metres per second is 1 mph?

1 mph = 0.44704 m/s, exactly, from the unit definitions.

How do I convert metres per second back to miles per hour?

Divide by 0.44704 — or multiply by 2.23693629205: 1 m/s = 2.23693629205 mph.

mph to m/s conversion table

Miles per hour (mph)	Metres per second (m/s)
1	0.44704
2	0.89408
3	1.34112
4	1.78816
5	2.2352
6	2.68224
7	3.12928
8	3.57632
9	4.02336
10	4.4704
15	6.7056
20	8.9408
25	11.176
30	13.4112
40	17.8816
50	22.352
60	26.8224
70	31.2928
75	33.528
80	35.7632
90	40.2336
100	44.704
150	67.056
200	89.408
250	111.76
500	223.52
1,000	447.04

Definitions: International yard and pound agreement (1959): 1 yd = 0.9144 m, 1 lb = 0.45359237 kg; adopted in NIST SP 811 B.8 and NIST Handbook 44 Appendix C · BIPM, The International System of Units (SI Brochure), 9th edition (2019), Tables 2, 4 and 8 — https://www.bipm.org/en/publications/si-brochure. Machine value of the factor: 0.44704.