Fuel & Gas Calculators — 15 Free Tools
Free calculators for fuel cost planning, gas mileage tracking, and fuel efficiency comparison. Calculate how much gas your trip will cost, your car’s MPG, compare fuel consumption, split gas costs, estimate EV charging costs, or convert between MPG, L/100km, km/L, and cost per mile.
Trip Planning & Fuel Economy
Gas Trip Cost Calculator
How much will gas cost for your trip? Enter distance, MPG, and gas price for total cost, gallons needed, cost per mile, and round-trip estimates.
MPG Calculator
Calculate your car’s miles per gallon from distance and fuel used, or convert between MPG (US), MPG (UK), L/100km, and km/L.
Fuel Consumption Calculator
See fuel consumption in all units at once: MPG (US), MPG (UK), L/100km, km/L. Compare efficiency across vehicles with annual cost estimates.
Budgeting & Comparison Tools
Gas Split Calculator
Split fuel costs fairly between passengers. Enter trip cost or calculate from distance and MPG, then divide among 2–10 people.
Monthly Gas Cost Calculator
How much do you spend on gas per month? Enter your daily commute, MPG, and gas price for weekly, monthly, and annual fuel costs.
Drive vs. Fly Calculator
Is it cheaper to drive or fly? Compare total driving cost (gas + tolls) with flight prices for solo travelers and families.
EV Charging Cost Calculator
How much does it cost to charge an EV? Compare electricity costs with gasoline for the same trip distance.
Unit Conversions & Cost Analysis
L/100km Calculator
Calculate fuel consumption in liters per 100 km. Convert to km/L, MPG (US), MPG (UK), and estimate annual fuel cost.
km/L Calculator
Calculate kilometers per liter from distance and fuel used. See L/100km, MPG (US), and MPG (UK) equivalents.
Cost per Mile Calculator
How much does driving cost per mile? See gas cost, total cost (with wear), and annual expenses. Compare with IRS mileage rate.
Annual Gas Cost Calculator
How much do you spend on gas per year? Enter your commute for daily, weekly, monthly, and annual cost plus CO2 emissions.
Fuel Economy Unit Converters
MPG to L/100km Converter
Convert miles per gallon to liters per 100 km. Supports US and UK (Imperial) gallons with 61 pre-calculated values.
L/100km to MPG Converter
Convert liters per 100 km to miles per gallon. Essential for reading European car specs and WLTP test figures.
MPG to km/L Converter
Convert miles per gallon to kilometers per liter, used in India (ARAI), Japan (WLTC), South Korea, and Brazil.
km/L to MPG Converter
Convert kilometers per liter to miles per gallon. Cross-shop Indian and Japanese cars with US-market competitors.
UK & Imperial Fuel Economy Converters
MPG (UK) to L/100km Converter
Convert UK Imperial MPG to L/100km. Formula: L/100km = 282.481 ÷ MPG(UK). 55 pre-calculated values.
L/100km to MPG (UK) Converter
Convert L/100km to UK Imperial MPG. Useful for comparing European car specs with UK fuel economy figures.
MPG (UK) to km/L Converter
Convert UK Imperial MPG to kilometers per liter. Bridges UK car specs with Indian and Japanese standards.
MPG to Miles per Litre Converter
Convert MPG to miles per litre (MPL). UK fuel sold in litres — see how far you go on each litre.
Miles per Litre to MPG Converter
Convert miles per litre back to MPG. Useful when calculating MPG from your own fill-up records.
US MPG to UK MPG Converter
Convert American MPG to UK Imperial MPG. UK figures are ~20% higher because Imperial gallons are larger.
Conversion Tables
Pre-calculated reference tables with CSV download, printable layout, and PDF export.
MPG → L/100km Table
Pre-calculated values with CSV download and print-friendly layout.
L/100km → MPG Table
Pre-calculated values with CSV download and print-friendly layout.
MPG → km/L Table
Pre-calculated values with CSV download and print-friendly layout.
km/L → MPG Table
Pre-calculated values with CSV download and print-friendly layout.
MPG (UK) → L/100km Table
Pre-calculated values with CSV download and print-friendly layout.
L/100km → MPG (UK) Table
Pre-calculated values with CSV download and print-friendly layout.
MPG (UK) → km/L Table
Pre-calculated values with CSV download and print-friendly layout.
MPG → Miles/Litre Table
Pre-calculated values with CSV download and print-friendly layout.
Miles/Litre → MPG Table
Pre-calculated values with CSV download and print-friendly layout.
US MPG → UK MPG Table
Pre-calculated values with CSV download and print-friendly layout.
Frequently Asked Questions
How do I calculate gas cost for a road trip?
Use our Gas Trip Cost Calculator: enter your distance, vehicle’s MPG, and current gas price. The formula is: Gas Cost = (Distance ÷ MPG) × Price per Gallon. Example: 300 miles ÷ 25 MPG × $3.50 = $42.00.
What is MPG and what is a good MPG?
MPG stands for Miles Per Gallon — it measures how far your car travels on one gallon of fuel. Higher MPG means better fuel economy. Average new sedan/wagon: ~37 MPG. Average new vehicle (all types including SUVs and trucks): ~28 MPG (2024 EPA Automotive Trends Report). Over 30 MPG is good for a car; over 40 is excellent.
How do I convert MPG to L/100km?
L/100km = 235.215 ÷ MPG. For example, 30 MPG = 235.215 ÷ 30 = 7.84 L/100km. Note: this uses US gallons (3.785 L), not Imperial gallons (4.546 L).
What is the average fuel cost per mile in the US?
About $0.10–$0.18 per mile, depending on vehicle efficiency and gas prices. At 25 MPG and $3.50/gallon: $0.14/mile. At 35 MPG: $0.10/mile.
Understanding Fuel Efficiency Units
MPG (Miles per Gallon)
Used in the US and UK. Higher = better. A US gallon is 3.785 L; a UK (Imperial) gallon is 4.546 L. So 30 MPG (US) ≈ 36 MPG (UK) for the same car.
L/100km (Liters per 100 km)
Used in Europe, Australia, and most of the world. Lower = better. A car doing 7 L/100km uses 7 liters to travel 100 kilometers.
km/L (Kilometers per Liter)
Used in Japan, India, and parts of Asia. Higher = better. Intuitive: “how far on 1 liter.” A car doing 14 km/L travels 14 km on one liter of fuel.
US Gallon vs Imperial Gallon
This is the most common source of confusion in fuel economy:
- US gallon = 3.785 liters (used in all our calculators)
- Imperial (UK) gallon = 4.546 liters (20% larger)
- Same car rated 30 MPG (US) = 36 MPG (Imperial)
Our calculators use US gallons by default. If you need Imperial gallons, use our Fuel Consumption Calculator which shows both.
Frequently Asked Questions
How do I calculate gas cost for a road trip?
Use our Gas Trip Cost Calculator: enter distance, MPG, and gas price. Formula: Gas Cost = (Distance ÷ MPG) × Price per Gallon. Example: 300 miles ÷ 25 MPG × $3.50 = $42.
What is MPG?
MPG stands for Miles Per Gallon — how far your car travels on one gallon of fuel. Higher MPG = better fuel economy. The 2024 US new car average is about 36 MPG combined (EPA).
How do I convert MPG to L/100km?
L/100km = 235.215 ÷ MPG. Example: 30 MPG = 235.215 ÷ 30 = 7.84 L/100km. Note: this uses US gallons (3.785 L), not Imperial gallons (4.546 L).
What is the average fuel cost per mile in the US?
About $0.12–$0.16/mile, depending on vehicle efficiency and gas prices. At 25 MPG and $3.50/gal: $3.50 ÷ 25 = $0.14/mile. At 35 MPG: $0.10/mile.
Related Converters
- Speed Converter — convert mph ↔ km/h
- Length Converter — convert miles ↔ kilometers
- Volume Converter — convert gallons ↔ liters
All fuel calculations use US gallons (3.785 L) unless otherwise noted. Gas prices and fuel economy figures are estimates based on 2025 US national averages. Actual costs vary by region, driving conditions, and vehicle.
