Waypoint Projection Calculator

What is Waypoint Projection?

Waypoint projection (also called coordinate projection or dead reckoning) calculates a new GPS coordinate by starting from a known point and moving a specified distance in a given direction. This technique is fundamental to multi-cache geocaching, navigation, and surveying.

Given a starting coordinate, a bearing (compass direction in degrees), and a distance, the projection calculator determines the exact GPS coordinates of the destination point.

How Waypoint Projection Works

The calculation uses spherical trigonometry to account for the Earth's curvature. The projection formula takes into account:

Starting latitude and longitude - Your reference point
Bearing - The compass direction (0° = North, 90° = East, 180° = South, 270° = West)
Distance - How far to project in your chosen unit
Earth's radius - Approximately 6,371 km at the equator

For short distances (under 100 km), the calculation is highly accurate. For longer distances, slight variations may occur due to the Earth's oblate spheroid shape.

Waypoint Projection in Geocaching

Multi-caches are the most common use case for waypoint projection. Cache owners often provide clues like:

"From the starting coordinates, walk 150 meters at bearing 045°"
"Project 500 feet at 270° from the posted coordinates"
"The final is 1.2 km at bearing equal to your answer"

Instead of trying to navigate in the field with a compass, geocachers can use waypoint projection to calculate the exact coordinates and navigate directly to that point.

Multi-Cache Stage Navigation

A typical multi-cache might have you visit several stages, each providing information for the next projection:

Start at posted coordinates, find a plaque with a bearing
At stage 2, find the distance for the next projection
Project to final coordinates and find the cache

Our projection tool lets you quickly calculate each stage's coordinates without mental math or compass navigation.

Understanding Bearings

A bearing is a compass direction expressed in degrees from 0° to 360°:

0° (or 360°) - North
45° - Northeast
90° - East
135° - Southeast
180° - South
225° - Southwest
270° - West
315° - Northwest

Bearings are measured clockwise from true north. In geocaching, bearings typically refer to true north rather than magnetic north, unless specifically noted.

True North vs Magnetic North

True north points to the geographic North Pole, while magnetic north points to where a compass needle aims. The difference (called magnetic declination) varies by location and changes over time.

GPS devices and this tool use true north. If you're given a magnetic bearing from a physical compass, you may need to adjust for declination based on your location.

Distance Units Explained

Our calculator supports multiple distance units commonly used in geocaching:

Meters (m) - Standard metric unit, most common in international geocaching
Kilometers (km) - For longer projections
Feet (ft) - Common in US geocaching, 1 meter ≈ 3.281 feet
Miles (mi) - For very long projections, 1 mile = 1.609 km

Common Projection Scenarios

Offset Cache

Some puzzle caches provide coordinates that are intentionally offset from the actual cache location. After solving the puzzle, you might learn: "The cache is 75 meters at bearing 120° from the posted coordinates."

Field Puzzle

Field puzzles often require you to find information at a location (like a memorial date or building number), then use that information as your bearing or distance for projection.

Letterbox Hybrid

Letterbox hybrids sometimes use traditional letterboxing clues like "walk 50 paces northeast." Converting paces to meters and northeast to a bearing (45°) lets you calculate precise coordinates.

Tips for Accurate Projections

Verify your starting coordinates - Double-check that you're using the correct starting point format
Consider GPS accuracy - Consumer GPS is accurate to about 3-5 meters, so short projections may have noticeable error
Watch for decimal vs. whole numbers - Is the bearing 45 degrees or 4.5 degrees? Is distance 150 meters or 15.0 meters?
Confirm the unit - Make sure you're using the same distance unit the cache owner intended

Related Navigation Tools

Waypoint projection works alongside other coordinate tools:

Coordinate Converter: Convert your results between DD, DDM, and DMS formats for your GPS device.
Bearing Calculator: Find the bearing from one point to another—useful for reverse-engineering a projection.
Distance Calculator: Measure straight-line distance between your projected point and another location.
Midpoint Calculator: Find the center point between two coordinates.