Work out what you can run, then what to run.
The calculations underneath Runsei work whether or not you ever sign up, so we put them on the site. Free and open — no account, nothing stored on our side, nothing emailed unless you ask.
Pace, finish time or distance — put in the two you know and the third appears. Then the split-by-split chart for race day, in kilometres or miles.
Work out a pace →LiveRace predictorFour models side by side, each with its own stated theory, fitted to your own results instead of one fixed exponent from 1977.
Predict your times →A full block to your goal race — every session, every week, paced off a race you actually ran. In review.
Coming laterWhat age is actually costing you, and how much of your old PB is still there. The real WMA tables, read the encouraging way round.
Coming laterWhat a gradient on the belt is worth in road pace.
Coming laterWhy these are free
Every one of them gives you a number that is right today. Keeping it right — when you get ill, travel, or have a week that does not go to plan — is the part we are building a product around. We would rather show you the gap than describe it.