Speedometer GPS Blog #

This blog explains how GPS measures speed and distance, and what that means when you’re driving, cycling, running or out on the water: why your car’s speedometer and your phone disagree, how accurate phone GPS really is, and what to do when a reading looks wrong. It’s the companion blog to Speedometer GPS, a free app for iPhone and Android that shows your speed straight from the satellites in km/h, mph or knots, with a speed limit alarm, a mirrored HUD mode for night driving, and saved trips with a lifetime odometer.

Start here #

• How accurate is a GPS speedometer? A test you can run
• How to check and calibrate a speedometer with GPS
• Odometer vs GPS distance: why your car and phone disagree
• GPS speedometer stuck at 0? Fixes for speed and distance
• GPS speed lag: why your speed app trails, and what to do
• Bike speed sensor vs GPS: which measures speed better?
• Why your GPS running pace is wrong, and how to fix it
• Boat GPS speed vs paddle wheel and pitot: which is accurate?
• Speed over ground vs speed through water, explained
• Battery tips for long drives and rides