Stopwatch Calculator

Do stopwatch arithmetic. Add, subtract, multiply, and divide race times.

Calculator for stopwatch arithmetic. Add, subtract, multiply, and divide race times without converting to seconds. Perfect for swimming and running / track / cross county. Intended for coaches, parents, and athletes.

Times are in HH:mm:ss.hh format (hours, minutes, seconds, hundredths). There is no need to type the colon or period, so "12345" is interpreted as "1:23.45" and ":30" is interpreted as "30.00".

Examples:

1. Calculating splits. Leg 4 started at 3:14.67 and ended at 4:11.50. What was leg 4's split?

    4 1 1 5 0 - 3 1 4 6 7 = 56.83

2. Calculating pace. Runner A finished the marathon in 3:26:54.48. What was her mile pace?

    3 2 6 5 4 4 8 ÷ 2 6 . 2 = 7:53.83

3. Calculating set duration. How long will 20 50s on :55 take to swim in practice?

    : 5 5 × 2 0 = 18:20.00

4. Calculating relay seed times. The four runners' individual times are 54.68, 57.32, 57.98, and 1:00.04. What would their relay time be?

    5 4 6 8 + 5 7 3 2 + 5 7 9 8 + 1 0 0 0 4 = 3:50.02

5. Converting between courses. Swimmer A swam a 5:44.86 short course yards 400 IM. What is that in meters? (1 yard = 0.9144 meters)

    5 4 4 8 6 × . 9 1 4 4 = 5:15.33