Pace Calculator

What this calculator does

If you've ever opened a spreadsheet just to answer one health & fitness question, this pace calculator replaces the whole workbook: type the numbers, read the result.

A pace calculator converts a distance and total time into a running pace expressed as minutes per kilometre and minutes per mile. This tool also gives you predicted race times for 5K, 10K, half marathon and marathon using the Riegel formula — a widely used model for estimating how a current effort translates to other distances.

Common mistakes

• Trusting GPS pace on winding trails or between tall buildings (drift)
• Not accounting for elevation and heat
• Applying 5K pace to a marathon — endurance decays with distance
• Comparing treadmill pace 1:1 with road pace
• Chasing splits on easy days instead of training the aerobic base

When to use it

Use pace to plan race strategy, set training zones (easy, tempo, threshold, interval), pace long runs correctly, and convert times between metric and imperial. Runners typically train 60–80% of miles easy, 60–90 sec slower per km than race pace.

Pro tips for the Pace Calculator

• Change one input at a time to see which lever actually moves the answer the most.
• Round-trip check: reverse the inputs to confirm the formula matches what you'd compute by hand.
• Bookmark this page: the URL and inputs are all you need to reproduce the exact result later.

Frequently asked questions

›What is a good running pace for beginners?

A comfortable, conversational pace — typically 6:30–7:30 /km (10:30–12:00 /mile) — is ideal for building an aerobic base.

›How accurate is the race predictor?

The Riegel formula is accurate within ~2–3% for well-trained runners with a similar training history at both distances. Under-trained marathoners often finish 5–15% slower than the 5K prediction.

›What pace should I run a marathon at?

Most non-elite marathoners run 60–75 seconds/km slower than their 5K pace. Practice marathon-pace runs of 60–120 minutes during training.

›How do I convert min/km to min/mile?

Multiply min/km by 1.609. Example: 5:00 /km × 1.609 ≈ 8:03 /mile.

›What is tempo pace?

Comfortably hard, roughly 25–30 seconds/km slower than 5K race pace. You should be able to say a short sentence but not hold a conversation.

›What is threshold pace?

The pace you could sustain for about one hour of racing — typically 10K to half-marathon race pace for most runners.

›Does elevation change my pace?

Yes. Every 100 m of climbing typically adds 20–40 seconds. Use grade-adjusted pace on hilly runs.

›What are negative splits?

Running the second half of a race faster than the first. It's the most efficient pacing strategy for distances 10K and up.

›How do I use pace zones in training?

Easy: +60–90 s/km over 5K pace. Marathon: +30–45 s/km. Threshold: +25–30 s/km. Interval: 5K pace or faster.

›Can I embed the Pace Calculator on my site?

Embedding isn't public yet, but you can link directly to this page — the URL is stable and shareable.

›Where does the formula come from?

The formula shown in the "How it works" section is the same one you'll find in standard health & fitness references — no proprietary tweaks or hidden weightings.