Calculator Inputs
Formula Used
Fuel Used = Distance × Fuel Consumption Rate
Fuel Used = Operating Hours × Burn Rate
Fuel Used (L) = Power (kW) × BSFC (g/kWh) × Load Factor × Hours ÷ 1000 ÷ Fuel Density
Adjusted Trip Fuel = Base Fuel × (1 + Adjustment %)
Idle Fuel = Idle Hours × Idle Burn Rate
Reserve Fuel = (Adjusted Trip Fuel + Idle Fuel) × Reserve %
Trip Cost = Total Planned Fuel × Fuel Price
CO₂ = Total Planned Fuel × Fuel Emission Factor
This page supports distance models, hourly burn-rate models, and engineering power models. That makes it practical for road vehicles, marine engines, generators, and custom equipment.
How to Use This Calculator
- Choose the method that matches the data you already know.
- Enter equipment type and fuel type for better defaults.
- Add distance, hours, or power data as needed.
- Enter route adjustments, idle use, reserve, and fuel price.
- Submit the form to see total planned fuel, cost, and efficiency.
- Use the chart to understand how fuel changes with distance or hours.
- Download the results as CSV or PDF for reporting.
Example Data Table
| Scenario | Method | Key Inputs | Estimated Fuel | Estimated Cost |
|---|---|---|---|---|
| Passenger car trip | Distance | 320 km, 7.2 L/100 km, 8% reserve | 24.88 L | 31.10 |
| Fishing boat run | Time | 6 h, 18 L/h, 12% reserve | 120.96 L | 145.15 |
| Diesel generator | Power | 85 kW, 220 g/kWh, 75% load, 4 h | 67.38 L | 80.86 |
| Marine transfer | Power | 180 hp, 235 g/kWh, 65% load, 3.5 h | 57.08 L | 74.20 |
Answers to Common Questions
Absent any data about speed, what would be the best estimate of fuel consumption?
If speed is unknown, use your most reliable measured average efficiency or hourly burn rate. For vehicles, recent L/100 km or km/L data is usually best. For engines and boats, use observed L/h or a power-plus-BSFC estimate at normal load.
How to estimate a boats fuel consumption
For a boat, the strongest estimate usually comes from hourly burn rate or engine power, BSFC, load factor, and operating hours. Add safety margin for wind, waves, hull condition, current, and reserve policy. If distance is known too, you can also derive fuel per nautical mile.
FAQs
1. Which method should I choose first?
Choose distance-based when you know trip length and average vehicle efficiency. Choose time-based when you know operating hours and burn rate. Choose power-based for engines, generators, or boats when engineering performance data is available.
2. Why include a reserve fuel percentage?
Reserve fuel adds a safety margin for uncertainty, diversions, weather, idling, and operating changes. It improves planning and helps prevent underestimating the total fuel you should carry or purchase.
3. Can this calculator work for boats?
Yes. Boats often fit the time-based or power-based method better than a simple road-efficiency model. Enter nautical miles if distance matters, and add a condition adjustment for sea state, current, or hull drag.
4. What is BSFC in the power method?
BSFC means brake-specific fuel consumption. It shows how many grams of fuel an engine needs to produce one kilowatt-hour of work. Lower BSFC usually indicates better fuel efficiency under comparable operating conditions.
5. Should I enter idle hours separately?
Yes, when idle time is meaningful. Idling can materially change total fuel use for vehicles, marine engines, and generators. Separating idle hours gives a more realistic estimate than only using moving or loaded time.
6. How accurate are the results?
Accuracy depends on your inputs. Measured historical data usually beats nameplate or brochure figures. Road grade, traffic, weather, cargo, trim, maintenance condition, and operator behavior can all change real consumption.
7. Why does speed matter sometimes but not always?
Speed helps when you need time estimates or when consumption changes significantly with operating point. But if you already know liters per hour, liters per 100 kilometers, or BSFC at a known load, speed is not always required.
8. Can I compare costs using different fuel-price units?
Yes. The calculator converts prices entered per liter, US gallon, or UK gallon into a common basis. That lets you compare cost outputs consistently even when input sources use different pricing units.