40-Yard Dash to MPH Calculator
Convert a 40-yard dash time into average speed in mph, km/h and m/s, with hand-time correction, 10- and 20-yard split speeds, speed score and NFL combine averages by position.
How it works
40 yards = 36.576 m · average speed = 36.576 ÷ time · mph = m/s × 2.23694 · km/h = m/s × 3.6 · speed score = weight(lb) × 200 ÷ time⁴ · electronic ≈ hand time + 0.24 s
A 40-yard dash time converts to an average speed over the whole run, not top speed. Forty yards is exactly 36.576 m, so dividing it by the time gives meters per second, which converts to mph and km/h. Because a sprinter spends the first several yards accelerating from a dead stop, the peak speed in the final 10–20 yards is clearly faster than this average. Enter the 10- and 20-yard splits under More options to see the speed of each segment; the last 20 yards (the “flying 20”) is the best simple estimate of top speed. Hand-held stopwatches react late at the start, so a hand time is converted to an electronic equivalent by adding 0.24 s (adjustable) before it is compared. With a body weight the calculator also gives the speed score, weight × 200 ÷ time⁴, a football analytics measure that rewards big players who run fast. About 100 is average for a running back, and the score is most useful for backs, receivers, tight ends and edge rushers. The position table compares your time with the average NFL combine results by position.
Worked example
A 4.5-second 40 covers 36.576 m, so the average speed is 36.576 ÷ 4.5 = 8.13 m/s. Multiplying by 2.23694 gives 18.18 mph (29.26 km/h). At 200 lb the speed score is 200 × 200 ÷ 4.5⁴ = 40,000 ÷ 410.1 = 97.5. That time is 0.27 s faster than the 4.77 s average of all combine athletes, worth about a 2.3-yard lead at the line. If the same run was hand-timed, its electronic equivalent is about 4.74 s, or 17.26 mph.
Sources: MockDraftable — NFL combine aggregate data by position · Pro Football Reference — NFL combine results · NIST — yard to meter (1 yd = 0.9144 m)
Frequently asked questions
Is this my top speed?
No. It is the average over the full 40 yards, including the slow acceleration phase from a standing start. Elite sprinters reach a peak of 20+ mph in the back half even when their average is around 18 mph. Enter your 20-yard split to see the speed over the last 20 yards, which is close to top speed.
Why do 40 times matter so much?
The 40-yard dash is the headline combine test for American football, roughly the distance a receiver or defensive back covers on a typical play. Tenths of a second separate draft rounds, which is why the conversion to mph gets so much attention.
Does hand timing change the result?
Yes. Hand-started times run about 0.2–0.3 s faster than fully electronic times because of the timer’s reaction lag, so a hand-timed 4.3 and an electronic 4.5 can describe the same athlete. Choose Hand-timed and the calculator adds 0.24 s (you can change it) before converting and comparing.
What is speed score?
A football analytics stat that combines size and speed: weight in pounds × 200 ÷ (40 time)⁴. A 220 lb back running 4.50 scores about 107. Around 100 is average for NFL running backs, and over 110 is excellent. Because the time is raised to the fourth power, a tenth of a second matters far more than a few pounds.
What is a good 40-yard dash time?
It depends on the position. At the NFL combine, receivers and cornerbacks average about 4.49–4.50 s, safeties and running backs about 4.56–4.59, linebackers 4.70, quarterbacks and tight ends about 4.76–4.82, and offensive linemen about 5.25–5.28.
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