1:45 half marathon pace

By Rai Ansar · Updated 17 October 2026 · Tables generated by this site's calculator and verified by independent automated calculation checks. How pages are made

Splits for a 1:45:00 half marathon

Even pacing holds one pace. The negative plan starts 2% slower and finishes 2% quicker: first half 53:02, second 51:58. Both reach 1:45:00 to the second. If you've never run one, negative splits explained shows how the shape works.

To plan a different finish time, open the split calculator with 1:45:00 filled in. For the same goal on a treadmill, the treadmill pace chart gives the speed to set.

Which pace to hold on the watch

The highlighted row is the slowest whole-second pace per mile that finishes under 1:45:00. The exact average rounded to the nearest second, 8:01, misses.

Courses are measured along the shortest route a runner could take, so a GPS watch usually shows more distance than the course (USATF). If yours reads 1% long, it has to show 7:55 a mile to finish under 1:45:00 on the clock. The pace converter switches any of these paces between miles and kilometres.

Printable pace band for 1:45:00

Print this page (Ctrl+P or Cmd+P) and only the band prints, 40 × 240 mm. The printable pace band page covers the 100% print setting and the 50 mm ruler check, and makes negative-split and run/walk bands for 1:45:00.

If the first 5K is slow: the catch-up pace

A slow start is the usual way a 1:45 half goes wrong, and the question afterwards is how much quicker the rest has to be. The table takes the even 1:45:00 plan, puts you 30, 60 or 120 seconds behind it at 5K, 10K or 15K, and gives the slowest whole-second pace per mile for the remaining distance that still finishes under 1:45:00. The later the deficit, the less distance there is to spread it over.

The last column compares with the exact goal pace, 8:00.6 per mile. These are the paces on paper; whether you can hold one late in a race is a separate question, which is the argument for the even or negative plans above.

What 1:45 predicts, and what it does not

The 5K and 10K rows are fair benchmarks: Vickers and Vertosick (2016) found Riegel's formula well calibrated up to the half marathon in 2,303 recreational runners. The marathon row (3:38:55) is where it breaks down. The same study found the formula's marathon predictions at least 10 minutes too fast for half of the runners, and adding weekly mileage improved the prediction. If a 1:45 half is your springboard to a sub-3:40 marathon, your weekly mileage matters as much as your half marathon time. If 1:45 is a step too far for now, the splits for a two-hour half are laid out the same way, with a printable band.

Common 1:45 half marathon mistakes

• Running 5:00 per km. It is the round number in your head, and it finishes in 1:45:29.
• Mixing 8:00 per mile with 4:59 per km. They are different paces; 4:59 per km is 8:01 per mile.
• Planning for 13.1 miles. The race is 13.1094 miles; the last 0.1094 mile takes 0:53 at 1:45 pace.
• Relying on watch pace. A watch reading 1% long must show 7:55 per mile for a sub-1:45 on the clock.

How the numbers are worked out

6,300 seconds over 21.0975 km is 298.61 seconds a km, which reads 4:59; rounded down to 4:58 and held for the whole race, it gives 6,287 seconds, or 1:44:47. Each checkpoint is the exact elapsed time rounded to the nearest second, so no split drifts more than half a second and the last row is 1:45:00.