Which calculator do you need?
Start from what you already have, not from the tool you have heard of. Find your row below and go straight to the one calculator that answers it.
Only picking one?
One honest race result feeds nearly every other tool here — training paces, marathon splits, qualifying checks. Without it you are calibrating against a guess.
Start from what you have
What could I run over a different distance?
Converts one honest race result into a realistic time at any other distance. This is the right first stop for almost everyone — most other tools work better once you have a predicted time to feed them.
How fast should my training runs be?
Turns a race time into easy, marathon, threshold, interval and repetition paces. Without this step, 'run easy' has no number attached to it and easy days drift too hard.
What splits do I run on race day?
Lays the goal across the full distance so you know the number to hold at every checkpoint, rather than doing arithmetic at mile 14.
Am I fast enough for Boston?
Compares your time to your age-group standard and, more usefully, to the buffer recent fields have actually needed.
Do I have a guaranteed NYC entry?
New York honours half-marathon times too, and applies no cut-off. Checking it is a different question from checking Boston.
Where are my training zones?
Sets zone boundaries from your threshold or max heart rate. Use this when you train by feel and heart rate rather than by pace.
What is a realistic pace in this weather?
Goal pace assumes cool conditions. This tells you how much slower the same effort will be, so a warm race becomes a pacing decision instead of a blow-up.
What is my effort-equivalent pace?
Compares a hilly run to a flat one at the same effort, so a slow uphill day is not misread as lost fitness.
What is my FTP and what are my bike zones?
The cycling equivalent of VDOT: one test number that sets every training zone on the bike.
What does this incline actually equal outdoors?
Converts belt speed and incline into an outdoor-equivalent pace, so indoor sessions land in the right zone.
Frequently asked
I have never raced. Which calculator should I start with?
None of them, yet. Run a hard, honest 5K on a flat course or a parkrun, then start with the race predictor. Every tool on this site is only as good as the input you give it, and a guessed time produces guessed paces.
What is the difference between the race predictor and VDOT?
The race predictor answers 'what could I run?' — one race time to another distance. VDOT answers 'how should I train?' — the same race time converted into daily training paces. Most runners want both, in that order.
Do I need the heat calculator if I train in the morning?
Only if your race is warm. It is a race-day and summer-block tool: it converts your goal pace into what the same effort will actually produce in the forecast conditions, which is the difference between a controlled race and a positive split.