How to use Wakewise · Methods, examples and report help
Fuel range and electrical planning
Range = fuel × (1 − reserve percentage) ÷ hourly consumption × speed. Battery capacity = watts × hours ÷ volts ÷ usable-capacity fraction.
For example, 100 US gallons, a 20% reserve, 5 gallons/hour and 6 knots gives 96 nautical miles. Confirm consumption against your vessel’s measured performance.
Range excludes changing weather, currents and fuel-system limitations. Hull speed applies to displacement hulls; scope and propeller figures are planning estimates.
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Common questions
How do I calculate boat fuel range with a reserve?
Multiply fuel aboard by the usable fraction after your reserve, divide by measured hourly fuel consumption, then multiply by cruising speed in knots. The result is nautical miles. Repeat with conservative consumption and speed assumptions.
What battery capacity do I need for onboard loads?
Enter total watts, hours of use, system voltage and the usable-capacity percentage appropriate to your battery. The estimate is in amp-hours. It excludes charging losses, inverter losses and starting-current requirements unless included in your load assumptions.