Compare calculators

Both calculators run independently — change the inputs on either side to compare results.

Race Time Predictor

Predict your finish time at any race distance using a recent result from a different distance. Ideal for setting realistic goals when stepping up from a 5K to a half marathon or full marathon.

Known Race Distance

Known Time (Hours) (hr)

Known Time (Minutes) (min)

Target Race Distance

Fill in the required fields to see your result.

Running

Marathon Time Predictor

Predict your marathon finish time from a recent 5K, 10K, or half marathon result using empirical scaling factors tuned to typical recreational runners. Use it to set a realistic goal before your first marathon or to validate a training cycle.

Race Distance (km)

Race Time (minutes)

Fill in the required fields to see your result.

Key differences

	Race Time Predictor	Marathon Time Predictor
Category	Running	Running
Inputs required	4	2
Result	Predicted Time (minutes)	Predicted Marathon Time (minutes)
What it does	Predict your finish time at any race distance using a recent result from a different distance. Ideal for setting realistic goals when stepping up from a 5K to a half marathon or full marathon.	Predict your marathon finish time from a recent 5K, 10K, or half marathon result using empirical scaling factors tuned to typical recreational runners. Use it to set a realistic goal before your first marathon or to validate a training cycle.