Marathon Split Calculator

Build a marathon pacing plan from a goal finish time by breaking the race into even splits at every checkpoint. A marathon is 26.2 miles or 42.195 kilometers, and holding a steady effort is the surest way to avoid blowing up in the final miles, so knowing your target time at each 5K and at halfway keeps you honest. Enter your goal finish as hours, minutes and seconds, choose miles or kilometers, and optionally add a negative split percentage so the second half is run slightly faster than the first. The tool computes your required pace per mile or kilometer and prints the cumulative clock time you should see at 5K, 10K, the half, 30K, 40K and the finish. Use it to write a pace band or set your watch alerts. All the math happens in your browser instantly.