Speed Timer - GPS Speedometer

Measure your vehicle's acceleration with GPS precision. 0-100, 0-200, and custom speed ranges with real-time gauges and detailed analytics.

Speed Timer is a precision GPS-based acceleration measurement tool designed for car enthusiasts, automotive journalists, and anyone who wants to know their vehicle's real-world performance.

MEASURE ANY SPEED RANGE Set custom start and end speeds or use built-in presets like 0-100, 0-200, 100-200, and 60-130 km/h. Switch between km/h and mph units instantly.

HOW IT WORKS

1. Select your speed range
2. Tap Start to arm the measurement
3. Accelerate — the app automatically detects when you cross the start speed
4. Timer stops precisely when you reach the target speed
5. View your corrected time with detailed analysis

PRECISION ENGINEERING

• Dual EMA (Exponential Moving Average) filtering for noise-free readings
• Sub-sample threshold crossing interpolation for accurate timing
• Automatic GPS bias and filter lag correction
• Confidence rating (High / Medium / Low) based on GPS accuracy and acceleration data

REAL-TIME SPEED GAUGE A beautifully designed gauge displays your current speed with smooth animations, color-coded status indicators, and live elapsed time during measurement.

DETAILED ANALYTICS Every measurement includes:

• Speed vs Time chart
• Acceleration vs Time chart
• Distance vs Time chart
• Speed vs Distance chart
• Corrected and raw times
• Maximum speed reached
• Average acceleration
• GPS accuracy metrics

COMPARE RUNS Side-by-side comparison of your last two runs with overlay speed charts and a detailed metrics table showing which run was faster.

HISTORY & EXPORT

• All measurements saved locally with up to 200 records
• Swipe to delete unwanted records
• Export individual runs as CSV
• Export full history as JSON backup
• Share data via any app

CUSTOMIZABLE

• Dark and light themes
• km/h or mph units
• Haptic feedback toggle
• Advanced tuning: deadband, snap-to-zero, EMA filter alphas, correction bias offset

PRIVACY FIRST Speed Timer works entirely offline. Your location data is used only for speed calculation and is never uploaded, shared, or stored beyond your device.

Note: GPS accuracy depends on device hardware and environmental conditions. For best results, use in open areas with clear sky visibility. Speed Timer is intended for use on private roads and closed courses only.