Tennis serve speed converter
Type a speed in any box. The others update, along with how long the returner gets.
mph to km/h, the short version
Multiply miles per hour by 1.609 to get kilometres per hour. Divide km/h by 1.609 to go back. Tournaments in the US and UK usually show mph; most of the rest of the world shows km/h.
| mph | km/h | Roughly who serves this |
|---|---|---|
| 60 | 97 | Newer adult players |
| 80 | 129 | Regular club players |
| 100 | 161 | Strong club and county players |
| 120 | 193 | Typical professional first serve |
| 140 | 225 | The biggest servers on tour |
These bands are rough guides. Height, technique and the radar gun all make a difference.
How long does the returner really have?
A court is 23.77 m (78 ft) from baseline to baseline. The time shown above assumes the ball holds its speed the whole way, which gives the shortest possible time. In reality air resistance and the bounce take a lot of speed off, and a serve typically arrives at around half the speed it left the racket. So the returner gets a little longer than the number suggests, but still well under a second on a fast serve.
Fastest serves on record
- 263.0 km/h (163.4 mph), Sam Groth, 2012. The fastest ever measured, at a Challenger event, though not recognised as an official ATP record.
- 253 km/h (157.2 mph), John Isner, 2016 Davis Cup. Widely listed as the fastest officially recognised serve.
- 220 km/h (136.7 mph), Georgina García Pérez, 2018. The fastest recorded serve by a woman.
Records get broken, so check a current source before settling a bet.
Where the speed is measured
Radar guns read the ball just after it leaves the strings, when it is at its fastest. That is why broadcast serve speeds look so much higher than the pace the returner actually deals with.