Fleet Fuel Spend Forecast Calculator (Free)
Forecast monthly and annual fuel spend using miles, MPG, and fuel price—then model best/base/worst scenarios and fuel price sensitivity.
Monthly forecast
Best / base / worst
Fuel price sensitivity
Inputs
Positive = efficiency improves, negative = worse MPG.
Optional: add % fuel due to idling/inefficiency.
Tip: If you’re building a budget, run a “worst case” with higher fuel price + higher miles + lower MPG.
Projected spend (monthly avg)
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Average across horizon
Projected spend (total)
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Across horizon
Projected gallons (total)
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Across horizon
Biggest drivers
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| Scenario | Total spend | Delta |
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| Month | Miles | MPG | Fuel price | Gallons | Spend |
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How to use this forecast
Fuel budgets swing because of two things: miles and fuel price. MPG matters too—especially when driver behavior changes (speeding, idle, harsh driving).
Budgeting tips
- Use a base case: current miles, current MPG, and current fuel price.
- Run worst case: higher price + higher miles + slightly lower MPG.
- Monitor monthly: compare actual to forecast and re-forecast quarterly.
Fuel Forecast FAQ
Should I forecast by month or by season?
Start simple with monthly. If seasonality is strong (snow routes, summer demand), increase miles in those months manually (export CSV and adjust).
How do I account for idling or route inefficiency?
Use the “idling adder” to add a % fuel overhead. For more precision, use the Idling Cost and Route Optimization tools.
What if I have multiple vehicle classes?
Run separate forecasts per class (light-duty vs heavy-duty) and combine totals. This is usually more accurate than a single blended MPG.
Disclaimer: Forecasts are estimates. Real-world MPG and miles vary with load, weather, traffic, and routes.