Boating Calculator

About Boating Calculator

Boating Calculator is a planning aid for anchoring, fuel range, and the speed/time/distance triangle - for a small recreational boat, not a chartplotter or navigation instrument.

Use it to check anchor scope, plan fuel for an out-and-back trip, or work the classic speed/distance/time triangle with an ETA, with the formula shown on screen so you can check the math. This is not a substitute for charts, local knowledge, tide/current tables, or seamanship - the skipper is responsible for the vessel.

ANCHOR
- Enter water depth, bow height above the water, and expected tidal rise
- Choose the rode type (all-chain or rope/chain) and the scenario (lunch hook, overnight, or storm)
- See the conventional scope ratio for that scenario and rode type
- Get the rode length to deploy and the swing radius (rode length plus boat length overall)
- Switch between feet and meters

FUEL
- Enter tank capacity, burn rate, and cruise speed
- Choose the classic one-third rule (one-third out, one-third back, one-third reserve) or a configurable reserve percentage
- See usable fuel, endurance in hours, and range in nautical miles
- See the point-of-no-return distance, including for a return leg burning fuel at a different rate than the outbound leg
- Work the speed/time/distance triangle in knots, statute mph, or km/h, with distance following the selected speed unit
- Get an ETA from a departure time and a computed travel time

BOATS
- Save named presets for your own boat's tank capacity, burn rate, and cruise speed
- Load a saved boat to fill the Fuel tab instantly

BUILT FOR ON-THE-WATER USE
- Fast entry with minimal taps
- Works offline
- No account required
- Saved boats and history stay on your device

This app is ad-supported. The calculators are available to use; watching a short ad unlocks saving results, calculation history, and saved boat presets.

If you want a straightforward anchor scope calculator, boat fuel range calculator, or a speed/time/distance/ETA tool for planning a day on the water, this app gives you the numbers with the formula shown.