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Runner's Splits

Runner's Splits, a small reckoner that computes in your browser and stores nothing. No account, no cloud, no telemetry.

Live · runs in your browser · no network

This is not a screenshot. It's the real tool, running right here: go on, put something in it.

Open the demo full-screen: /demos/runners-splits.html

Forged into a knife, this tool ages with use: the blades you reach for wear soft, entries you tend keep their bloom, and the years travel with the file through every reforge.

You want to finish in under two hours; the question is what that means at kilometre one, when you feel immortal and are about to ruin everything. Runner's Splits does the pace arithmetic — target time into per-kilometre splits, or your pace into a projected finish — so the plan exists before the gun goes. It computes and stores nothing; the legs keep their own records.

KindReckoner · computes, stores nothing
CategoryReckoners
Weight1
Manual:

Standing facts

In ten years

Runner's Splits computes; it doesn't hoard. Open the file in 2036 and it will do the same arithmetic it does today, because the arithmetic is written into the file and nothing about it needs a server to agree.

If Offline.Ltd closes tomorrow, nothing on your machine notices. That isn't a marketing promise; it's simply what a file is.

Getting your data out

There is nothing locked in to get out: copy the numbers, or keep the file. Either way you owe no one a request form. No export queue, no "we'll e-mail you a link within 48 hours", no format that only one vendor can read.

Copy the file to a USB stick, a NAS, a folder your devices already sync. It runs on Windows, macOS, Linux, Android and iOS, online or off, because a browser is the only thing it ever needed.

Who else sees this

Nobody. Runner's Splits works out its answer in your browser and forgets it the moment you close the tab: there is no store to breach, because nothing is stored. There is no account, no telemetry, no analytics, and no code in the file that opens a network connection, pull the cable and watch it carry on working. How privacy works across the Reckoners tools →

Questions people ask

01

How do I calculate my race pace for a target finish time?

Give it the distance and the time you are aiming for, and it computes the pace and the splits. Write them on your hand, tape them to your bottle — the plan is now portable.

02

Is this pace calculator free, offline, and account-free?

All three. It is one HTML file that runs in your browser with no connection, computes on the spot, and stores nothing — your ambitions never leave the page. It also cannot sell you shoes.

03

Can it tell me what finish time my usual pace gives?

Yes — the arithmetic runs both directions. Enter your pace and the distance and it projects the finish, which is a useful reality check before you promise anyone a personal best.

Go deeper on Runner's Splits

More Reckoners

Fits your knife at weight 1. Nothing here is final, Knife follows Life. Reforging within your tier is free, forever. Add it, drop it, reforge it later; the file stays yours either way.

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