Last updated: May 2026
Calculate exact fuel costs for any trip or estimate your annual fuel spend. Compare vehicles side-by-side.
Trip Details
Annual Driving Details
Fuel Efficiency Reference Guide
| Efficiency Tier | MPG Range | Common Examples | Annual Cost* |
|---|---|---|---|
| Poor | Under 20 MPG | Large trucks, SUVs, performance cars | — |
| Average | 20–30 MPG | Sedans, mid-size SUVs, minivans | — |
| Good | 30–40 MPG | Compact cars, small hybrids | — |
| Excellent | 40+ MPG | Hybrid sedans, plug-in hybrids | — |
* Based on 15,000 miles/year at current gas price from Annual tab ($3.50 default).
MPG formula: Gallons needed = Distance ÷ MPG. Total cost = Gallons × Price per gallon. Cost per mile = Price per gallon ÷ MPG.
Metric (L/100km): Liters needed = Distance × (L/100km) ÷ 100. Total cost = Liters × Price per liter.
Annual cost: Annual gallons = Miles per year ÷ MPG. Annual cost = Annual gallons × Gas price. Monthly = Annual ÷ 12.
Why low-MPG improvement matters more: Going 15→20 MPG saves 167 gallons/15k miles. Going 30→60 MPG saves only 250 gallons. The relationship is hyperbolic, so early gains are most valuable.
Fuel costs vary by region, driving conditions, and vehicle maintenance. Electric vehicle comparisons are not included. Prices shown are estimates only.
Fuel cost is one of the most significant and variable components of vehicle ownership. At its core, the calculation is straightforward: divide the miles you need to travel by your vehicle's fuel economy (MPG) to find how many gallons you'll burn, then multiply by the price per gallon. What makes it complex in practice is that MPG ratings differ substantially between city and highway driving, vehicle type, driving habits, and even tire pressure and load weight.
Understanding your real-world fuel economy — not just the EPA sticker estimate — is the first step to accurately budgeting fuel costs. Most drivers see 10–20% lower MPG than the official rating in mixed real-world conditions. Tools like this calculator let you plug in your actual observed MPG to get a more honest picture of what each trip or month of driving is truly costing you.
| Vehicle Type | City MPG | Highway MPG | Annual Fuel Cost (15k mi) |
|---|---|---|---|
| Compact sedan | ~32 | ~40 | ~$1,500 |
| Midsize SUV | ~22 | ~30 | ~$2,200 |
| Full-size truck | ~17 | ~23 | ~$3,000 |
| Hybrid sedan | ~52 | ~48 | ~$900 |
| Electric vehicle | MPGe 100+ | MPGe 100+ | ~$600 (electricity) |
| Minivan | ~20 | ~26 | ~$2,500 |
| Sports car | ~18 | ~26 | ~$2,800 |
How do you calculate fuel cost for a trip?
Divide the trip distance by your vehicle's MPG to get gallons needed, then multiply gallons by the current gas price. For example: 300 miles ÷ 30 MPG = 10 gallons × $3.50/gal = $35.00 in fuel. For metric users, multiply distance in km by L/100km ÷ 100 to get liters, then multiply by price per liter.
What factors affect fuel economy (MPG)?
Key factors include driving speed (highway speeds above 65 mph reduce efficiency sharply), acceleration and braking habits, vehicle weight and aerodynamics, tire inflation, air conditioning use, engine condition, and fuel quality. Cold weather can reduce MPG by 10–20% due to longer warm-up times and increased engine friction.
Why is city MPG lower than highway MPG?
City driving involves frequent stops, starts, and idling — all of which burn fuel without covering distance. Highway driving at a steady speed is far more efficient because the engine operates in a consistent, optimized range. Hybrids are an exception: their regenerative braking recaptures energy during city stops, which is why some hybrids have higher city MPG ratings.
How much does gas cost per mile?
Cost per mile = Gas price ÷ MPG. At $3.50/gal and 28 MPG, you pay $0.125 per mile. At $4.00/gal and 20 MPG (a common SUV), it's $0.20 per mile. Over 15,000 annual miles, the difference between those two scenarios is $1,125 per year.
Does driving speed affect fuel economy?
Yes, significantly. Most vehicles reach peak fuel efficiency between 45–55 mph. Above 65 mph, aerodynamic drag increases exponentially and fuel economy drops rapidly — roughly 1–2% for every mph above 60 mph. Slowing from 75 mph to 65 mph on a long highway trip can improve MPG by 10–15% and meaningfully reduce trip fuel cost.