Swimming Pace Calculator: Pace per 100 m
SWIMMING PACE CALCULATOR
Every length.
Every 100.
Work out your pace per 100 metres or yards from any swim, predict your time for other distances, and find your critical swim speed.
Training on land too? Work out running pace and race times.
Running pace calculatorBEHIND YOUR NUMBER
A little understanding
goes a long way.
How are other distances predicted?
We use Riegel’s formula, which assumes you slow slightly as distance increases. It works best for distances within about 4× of the swim you entered.
T₂ = T₁ × (D₂ ÷ D₁)^1.06
What is critical swim speed (CSS)?
Roughly the pace you can hold for about 30 minutes, used to set training zones. Swim a hard 400 and a hard 200, then CSS pace per 100 = (T400 − T200) ÷ 2.
How accurate is this?
It gives a sensible starting point based on widely used formulas and sizing guides. Brands, conditions and personal preference vary, so treat it as a guide and check with a coach, fitter or specialist shop.