How accurate is GPS for running?

Modern GPS watches are typically 1-3% accurate in open conditions. In urban canyons or dense forests, error can increase to 3-5%.

Why does my GPS show more distance than the race?

GPS tracks your movement in a zigzag pattern rather than the ideal racing line. Tangent-cutting (running the shortest path through bends) can reduce actual distance, but GPS adds extra distance from signal bounce.

How can I improve GPS accuracy?

Wait for full satellite lock before starting. Run on open roads. Use multi-band GPS if available. Update your watch firmware regularly.

RunCalcs

GPS Accuracy Calculator — GPS Measurement Error

Estimate GPS measurement error on your running routes.

GPS Distance

Environment

How We Calculate This

GPS Error Estimation

True Distance = GPS Distance ± Error %

Error rates vary by environment: Open = 1%, Suburban = 2%, Urban = 3%, Forest = 4%, Mountains = 5%.

Frequently Asked Questions

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Last updated: February 2026

All calculations are estimates. Always consult a coach or medical professional for personalised training advice.