Free pace check · Half marathon · nothing you type leaves this page

Are you on pace for a half marathon? The miles a week it takes from here.

The weekly distance between now and race day, from what you’ve already run — and whether your weeks hold it.

Working it out…

Questions

The weekly number, in plain words.

How many miles a week does a half marathon take?
Half-marathon plans commonly add up to 200–300 miles. Add your plan’s total if you have one. Spread evenly, 250 miles is 20.8 miles a week over 12 weeks, 15.6 miles over 16 weeks and 12.5 miles over 20 weeks.
What if I’m behind on training for a half marathon?
Divide what’s left by the weeks left: that is your weekly number from here. With 125 miles left and 8 weeks to go it’s 15.6 miles a week; with 6 weeks to go, 20.8 miles. Every week that slips raises it, which is why it pays to check your pace each week rather than near the end.
How can I check each week that I’m on track for a half marathon?
Ceresis Core turns a half marathon into a weekly target. You log what you did in one line; it measures every week against that target, says how far ahead or behind you are, and plans the catch-up over the days left. Pace checks and the weekly review are on the free plan and work without AI.

The plan around it

One number at the centre. What holds it up, in orbit.

An example plan for a half marathon: the weekly number, and the sleep and routine that decide whether you keep it. Drag it, tilt it, share it with someone who keeps you honest.

Bringing the map up…

Drag a node to move it · drag space to pan · scroll or pinch to zoom · open a tracker to name its readings

Solid bodies are on target this week; hollow ones are short. Make it yours: edit this plan

Knowing the number is the easy part

Weeks slip one missed evening at a time. Ceresis measures what you actually do against that weekly number, names the day you fall behind with a catch-up plan that fits the days left, and sends a weekly review with one change for next week. Free, without AI.

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