Personal best confetti

Here is your improvement and what your new time suggests for other distances.

Your details

New personal best!

450 pieces of confetti

0:45 faster, 2.6% better

New pace5:33 per km
Equivalent 5K27:45
Equivalent 10K57:51
Equivalent half marathon2:07:39

Ten pieces of confetti for every second you took off. Equivalent times use Riegel's formula, which works best between 5K and the half.

The working

5K from 28:30 to 27:45

Forty five seconds faster is 2.6% better, and ten pieces of confetti a second gives 450 pieces. Your new pace is 5:33 per km, and the Riegel formula suggests about 57:51 for 10K and 2:07:39 for a half marathon.

Riegel

Time = old time x (new distance / old distance) to the power 1.06

Peter Riegel's 1981 formula works well from 5K to the half marathon. For a marathon it tends to be optimistic unless you have trained for the distance.

What next

Ideas

Enjoy it: rest and recovery matter
Write down what went well
Try a new distance or a different goal

Read with care

What this cannot tell you

Check your timeWe trust your watch.
Promise future timesEquivalents are estimates.
Clean up the confettiIt is virtual.

Questions

Common questions

What is a good 5K improvement?

Any improvement is good; beginners often drop minutes in the first year.

How accurate is Riegel?

Usually within a few per cent for similar distances.

How often can I set a PB?

Early on, often; later, less often, which makes each one sweeter.

What is the formula?

New time equals old time times the distance ratio to the power 1.06.

Sources

Last checked 21 October 2026. Spotted something wrong? Tell us and we will fix it.

Stop and get help

Stop and get help if you have chest pain, feel faint or are unusually breathless, and call 999 if chest pain does not go away. Check with your GP before stepping up if you have a heart, lung or joint condition.