Race Time Predictor

Riegel formula, all distances

Quick Answer

Race Time Predictor: Riegel formula, all distances. Race Time Predictor uses standard health formulas to compute accurate results instantly.

Known result distance

Hours

Minutes

Seconds

Known：10K 25:00（pace 2'30"/km）

Predictions below ↓

Distance	Riegel	Cameron	Pace needed
5K	11:59	—	2'24"/km
Half	55:10	4:40:55	2'37"/km
Full	1:55:00	9:21:51	2'44"/km

Formula

1Riegel: T₂ = T₁ × (D₂/D₁)^1.06
2Cameron (for half/full marathon): accounts for endurance fade, more conservative
3Base fitness:
410K 25:00 = 2'30"/km

Prediction accuracy notes

Short → long	Optimistic; needs endurance base
Long → short	Fairly reliable
Trained runner	±2-3% error
Casual runner	Add 5-10% to predictions

💡 The 1.06 exponent captures endurance fade — pure speed scaling would use 1.0. Riegel from a recent 10K race is the gold-standard marathon predictor; add 5-10 min if your long runs are under 32km. Cameron tends to be more accurate for marathon from shorter distances.

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How to Use

Enter body metrics: fill height, weight, age etc. as prompted by the Race Time Predictor.
Read value and grade: results appear instantly with an authority-based classification.
Check reference tables: confirm your range and healthy targets against the tables on this page.
Back-solve your goal: adjust inputs to see what it takes to reach a target.

Key Points

Race Time Predictor is a free online health tool — open and use, no sign-up.
All calculations run locally in your browser; your data never leaves the device.
Key capability: Riegel formula, all distances.
Results come with formulas and reference tables so you can verify every number.

Formula & How It Works

Race Time Predictor formula

Race Time Predictor uses standard health formulas to compute accurate results instantly.

FAQ

How do I use the Race Time Predictor?

Open the page and fill in the input fields — results update automatically. Riegel formula, all distances.

Are the results accurate?

Results follow published international standards (WHO, ACE, IOM) and are for reference only.

Can this replace medical advice?

No. Always consult a qualified healthcare professional for health decisions.

Is it free? Do I need to sign up?

Completely free. No registration, login or download required.

Does it work on mobile?

Yes. The responsive design works on all devices.

Related Guides

Source & Updates

Based on WHO, ACE, IOM and other published international standards. Last updated: 2025-07

Authoritative sources:

Last updated: 2026-08-07

Formulas and content on this page are reviewed by the YiJianSuan team. For reference only — official sources prevail.

Cite this page: YiJianSuan. Race Time Predictor[EB/OL]. https://www.yijiansuan.com/en/c/health/running-predict

Results provided by this tool are for reference only and do not constitute professional advice.