How do you convert km/h to mph?

Multiply km/h by 0.621371 to get mph, or divide mph by 0.621371 to go back. For example, 200 km/h × 0.621371 ≈ 124.3 mph. The factor comes from one mile equalling 1.609344 kilometres.

How do you convert to metres per second?

Divide km/h by 3.6 to get m/s, since one hour is 3600 seconds and one kilometre is 1000 metres. So 200 km/h ÷ 3.6 ≈ 55.6 m/s. To convert mph to m/s, multiply by 0.44704.

What is a fast tennis serve?

ATP men's first serves average roughly 185 km/h (115 mph) and WTA women's first serves average roughly 160 km/h (100 mph). Serves above 210 km/h (130 mph) are elite, and the recorded men's record is about 263 km/h (163 mph).

Why are serve speeds quoted differently at events?

Most tournaments outside North America display km/h, while events in the United States usually display mph, which is why the same serve looks like 200 in Australia and 124 at the US Open. This converter lets you compare them on equal footing.

Is radar speed the speed off the racquet?

Serve radar measures the ball's peak speed just after impact, before air resistance slows it. By the time the ball reaches the returner it has lost a substantial fraction of that speed, so the radar number is the launch speed, not the speed at the baseline.

What is the Tennis Serve Speed Converter?

Enter a tennis serve speed in km/h, mph, or m/s and get instant conversion to the other two units, plus a comparison to ATP and WTA average first-serve benchmarks and the fastest serves on record. It runs free in your browser on Gera Tools, with nothing uploaded.

Tennis Serve Speed Converter

Name: Tennis Serve Speed Converter
Creator: Gera Tools
License: https://creativecommons.org/licenses/by/4.0/

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Serve speeds are quoted in km/h at most tournaments and mph in the United States, which makes comparing players awkward. This converter turns any serve speed into all three common units — km/h, mph, and m/s — and shows where it sits against ATP and WTA benchmarks.

How it works

The conversions use exact factors derived from the definition of a mile and an hour:

mph  = kmh × 0.621371
m/s  = kmh ÷ 3.6
kmh  = mph ÷ 0.621371 = mph × 1.609344
m/s  = mph × 0.44704

Enter a speed in any unit and the tool normalises it to km/h internally, then converts out to the other two so all three always agree.

Worked examples

For example, a 200 km/h serve converts to:

200 × 0.621371 ≈ 124.3 mph
200 ÷ 3.6 ≈ 55.6 m/s

A 120 mph second serve converts to:

120 × 1.609344 ≈ 193.1 km/h
120 × 0.44704 ≈ 53.6 m/s

Putting the numbers in context

Knowing a serve speed in multiple units makes it far easier to compare across coverage. The same delivery that reads “200” on a Wimbledon scoreboard reads “124” at the US Open — same ball, same pace, different unit convention.

According to the FAQ above, ATP men’s first serves average roughly 185 km/h (115 mph) and WTA women’s first serves average roughly 160 km/h (100 mph). A serve above 210 km/h (130 mph) is elite-level pace. The men’s recorded radar maximum is around 263 km/h (163 mph).

For recreational players, typical club-level first serves sit somewhere between 130–160 km/h (80–100 mph), while beginners often serve between 80–110 km/h (50–68 mph). Knowing where your serve falls on that scale can guide whether pace or placement should be your next coaching focus.

The radar caveat

Serve radar measures the ball’s peak speed just after racquet impact, before air resistance and spin act on it. By the time the ball crosses the net, it has shed a meaningful fraction of that speed. So a 200 km/h radar reading does not mean the returner sees 200 km/h — it is the launch speed at the strings, not the arrival speed at the baseline. Reaction time calculations should account for this.