Fuel Economy Converter

How to use this calculator

1. Enter your vehicle’s MPG (real-world or sticker).
2. See the equivalent L/100km and Km/L instantly.
3. Try city vs highway MPG to see the range of metric values.
4. Reverse a metric rating by converting it to MPG (235.215 ÷ L/100km) if needed.
5. If you’re comparing imperial gallon figures, convert MPG (imp) to MPG (US) by dividing by ~1.201, then run the tool.

Inputs explained

MPG

Miles per gallon figure to convert; use observed MPG for accuracy or label MPG for comparisons.

When to use it

• Comparing US MPG to metric ratings when shopping international models or reading European/Canadian reviews.
• Planning road trips abroad and translating your car’s MPG into local L/100km signage.
• Checking consumption targets for fleets that report in different units.
• Benchmarking hybrids, trucks, or motorcycles across MPG, L/100km, and Km/L.
• Translating a friend’s Km/L brag into MPG to see how it stacks up.
• Normalizing fuel economy when evaluating used imports that list imperial MPG on the window sticker.
• Explaining efficiency differences to customers when selling vehicles across markets.
• Aligning corporate sustainability reports that quote fuel use in mixed units.
• Converting test drive results (e.g., km traveled per liter refilled) into MPG for US-based teammates.
• Training sales or support teams that need quick, accurate US-to-metric fuel economy conversions.

Tips & cautions

• Real-world MPG often differs from EPA/label values—use your own trip computer or tank averages for precision.
• Higher MPG means lower L/100km; they move inversely.
• If you only know L/100km, divide 235.215 by that number to get MPG; then re-enter MPG to double-check.
• Diesel and hybrid ratings can be high; ensure you’re comparing same fuel type and driving mix.
• City vs highway MPG differ—convert both to understand your realistic range.
• If you have imperial MPG, convert to US MPG by dividing by ~1.201 before using this calculator.
• For EVs using MPGe, convert MPGe as if it were MPG to get rough L/100km-equivalent energy usage, but note it’s not liquid fuel.
• When comparing WLTP vs EPA ratings, expect WLTP to read optimistically; use real-world MPG where possible.
• If you track fuel with receipts, divide miles driven by gallons pumped to get actual MPG before converting—this removes trip computer bias.
• Use decimal precision on MPG input (e.g., 27.5) to get tighter L/100km outputs when benchmarking close competitors.
• If your car displays Km/L, convert it to MPG before sharing with US audiences to avoid confusion.
• Keep rounding in mind: small MPG differences can materially shift L/100km at higher efficiency levels (e.g., 60 vs 58 MPG).
• Pure unit conversion—does not account for load, driving style, terrain, weather, or fuel type.
• Uses US gallon (3.785 L). Imperial gallon conversions differ (~1.201×).
• Does not estimate fuel cost or range; pair with a trip cost/fuel price calculator for budgeting.
• Does not handle CO2 grams/km or kWh/100km; this is liquid-fuel focused.
• WLTP/JC08/CLTC test cycles vary; this tool only reconciles units, not test methodology differences.

Worked examples

Deep dive

FAQs

Which gallon is used?

US gallon (3.785 liters). For imperial gallon, multiply US MPG by ~1.201 to convert.

Why does L/100km drop when MPG rises?

L/100km measures fuel consumed per distance, so lower is better; MPG measures distance per fuel, so higher is better—they move in opposite directions.

Can I use this for any vehicle type?

Yes. It’s a pure unit conversion for cars, trucks, motorcycles, or fleets. Just enter the MPG you have.

Can I compare WLTP vs EPA with this?

You can convert units, but test cycles differ. Use real-world MPG where possible, then convert for a fair comparison.

Does this apply to flex-fuel (E85) or diesel?

Yes for unit conversion, but be aware MPG can vary by fuel type. Enter the actual MPG for the fuel you’re using.

Can I estimate CO2 or cost from this?

Not directly. Pair the output with fuel carbon intensity or price to estimate emissions or trip cost.

What about plug-in hybrids with mixed electric/gas miles?

This tool converts a single MPG figure. For PHEVs, compute your blended MPG (gas miles ÷ gallons used) for the trip, then convert that value.

Do I need to adjust for altitude or cold weather?

Those factors change real MPG but not the conversion. Use the MPG actually observed in your conditions for best results.

Can I input Km/L directly?

Convert Km/L to MPG first: MPG = Km/L ÷ 0.425144. Then enter that MPG here to see L/100km and Km/L echoed back for validation.

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