Magnetic Declination Calculator

Estimate magnetic declination (compass adjustment) based on your location. Calculates the difference between true north and magnetic north.

Results

Visualization

How It Works

Magnetic declination is the angle between true north and magnetic north. In the western US, declination is typically 10-15 degrees east. In the eastern US, it's 5-20 degrees west. The mnemonic "East is least, West is best" reminds you: for east declination, subtract from compass bearing; for west, add. Declination changes about 0.1 degrees per year. Note: this calculator provides estimates — use NOAA's online tool for precise values.