Automotive Calculators

Miles Per kWh to kWh/100 km Converter

2026-09-24 7 min

Convert US EV efficiency to metric consumption instantly.

Entered: 3.50; mi/kWh
Consumption: 17.75; kWh/100km

Calculator

Efficiency(mi/kWh) Help

mi/kWh

Miles per kWh

Results update live as you type

Live statistics

Entered

3.50

mi/kWh

Consumption

17.75

kWh/100km

Driving plans — pick your profile

Plans adjust the projected fuel use so estimates match how you actually drive. Your measured MPG stays untouched.

Results

Normal

Entered

3.50mi/kWh

Value entered

Consumption

17.75kWh/100km

Exact metric equivalent

Averaged inputs beat single-tank readings. Plans scale projections only.

Visualizations

Consumption sensitivity

22.2x0.8

19.7x0.9

17.8x1.0

16.1x1.1

14.8x1.2

Metric consumption

17.8kWh/100km

035

Formula

How Miles Per kWh to kWh/100 km Converter is computed from its inputs, with every derived figure shown.

kWh/100km = 62.137 / mi/kWh

Alternative Form

62.137 = 100 / 1.60934

Variables

Symbol	Name	Unit	Description
E	Efficiency	mi/kWh	US figure

Explanation

Miles convert at 1.60934 per km; scaling 100 km through gives the exact 62.137 constant.

Derivation

Miles convert at 1.60934 per km; scaling 100 km through gives the exact 62.137 constant.

Step-by-Step Calculation

Follow each step to understand how the result is calculated from your inputs.

Step 1

Set efficiency.

Efficiency

Value:3.5 mi/kWh

Intermediate: 3.5 mi/kWh

Result: Accepted

Step 2

Divide the constant by the entered efficiency.

kWh/100km = 62.137 / mi/kWh

Efficiency:3.5 mi/kWh

Intermediate: y = 62.137 / 3.50

Result: 17.75 kWh/100km

Final Answer

3.50

Worked Examples

See how the calculator works with different scenarios.

Scenario

Convert 3.5 mi/kWh.

Inputs

Efficiency:3.5 mi/kWh

Calculation

62.137 / 3.5 = 17.75.

Result

17.75 kWh/100km.

Interpretation

17.75 kWh/100km.

Understanding Your Result

Your Result: Entered: 3.50 mi/kWh

Typical range: 3.5 mi/kWh equals 17.8 kWh/100 km.

What This Means

Metric consumption from any US efficiency figure.

Why It Matters

Reviews cross markets; exact conversion keeps comparisons honest.

Professional Interpretation

Convert then compare against local sticker figures directly.

How the plan factor applies

The Eco (x0.85), Balanced (x1.0) and Performance (x1.2) plans scale projected fuel use and cost, never the measured conversion itself.

Measured vs projected

Inputs you measure stay untouched by plans; only forward projections carry the plan multiplier.

Recommendations

•kWh math works across every EV and charger
•Charging efficiency separates wall energy from battery energy
•Rate-aware costing prices each charging mix fairly
•Degradation tracking informs warranty and resale decisions

Learn — fuel economy, deeply

Electric driving replaces gallons with kilowatt-hours. The core ratios are efficiency (miles or km per kWh, or kWh per 100 km), charging time (energy divided by power times efficiency), and cost (energy times electricity rate).

1 · Where the gallon goes (energy path)

Engine heat

60–70% lost

Coolant + exhaust carry most energy away. Hybrids recover some via Atkinson cycle + regen.

Driveline

5–15% lost

Transmission, differential, accessories. CVTs and 8–10 speed autos lose less.

Aero drag

∝ v²

Doubles from 55→78 mph. Roof boxes hurt more than trunks.

Rolling + brakes

10–20%

Tires, weight, stops. Regen braking (hybrid/EV) reclaims city braking energy.

2 · What EPA / WLTP ratings actually mean

City cycle — stop-and-go, 21 mph average, idle included. Hybrids shine here (regen + engine-off).
Highway cycle — steady 48 mph average with gentle accelerations. Aero and gearing dominate.
Combined — 55% city + 45% highway weighting. The single number most drivers should compare.
Real-world gap — expect 5–15% below the sticker with normal driving; hypermilers can beat it, aggressive drivers miss by 25%+.
MPGe — 33.7 kWh = 1 gallon-equivalent. A 120-MPGe EV uses ~⅓ the energy per mile of a 35-MPG car.

3 · Factor-impact table — what moves your number most

Factor	Typical impact	Why
Speed above 55 mph	−5 to −25%	Aero drag rises with v². Each 5 mph over 55 ≈ +$0.30–0.50/gal equivalent.
Aggressive driving	−10 to −30%	Hard acceleration + braking wastes kinetic energy, especially in the city.
Under-inflated tires (−5 PSI)	−2 to −4%	Higher rolling resistance. Check monthly; pressure drops ~1 PSI per 10°F.
Roof rack / cargo box	−5 to −25%	Empty rails ≈ −5%; loaded box at highway speed up to −25%.
Excess weight (+100 lb)	−1 to −2%	Matters most in stop-and-go. Clean the trunk before long trips.
A/C at city speed	−5 to −15%	At highway speed A/C beats open windows (drag). Use recirculation.
Cold weather (20°F vs 77°F)	−10 to −20%	Rich warm-up mixture, thicker fluids, winter-blend fuel, heater load.
Clogged air filter / bad O2 sensor	−4 to −40%	A failed oxygen sensor alone can cut economy by up to 40%.
Idling	0 mpg	0.2–0.5 gal/hr burned standing still. Restart beats 30 s+ idling.
E10 → E85 fuel switch	−15 to −30%	Ethanol carries less energy per gallon; flex-fuel range drops accordingly.

Winter playbook

• Expect −10 to −20% on short trips; combine errands on one warm engine.
• Tires lose ~1 PSI per 10°F — re-inflate monthly.
• Idle 30 s max, then drive gently; cabin heat comes faster under light load.
• Winter-blend fuel has slightly less energy — a 2–3% seasonal dip is normal.

Summer playbook

• City: windows down under ~45 mph; highway: A/C + recirculation beats open windows.
• Park in shade; ventilate before blasting A/C.
• Hot asphalt softens tires — still check pressure, heat raises it.
• Roof cargo hurts most in summer road-trip season — move it inside or to a hitch carrier.

4 · Measure like a pro (the 3-tank protocol)

Fill to first click at the same pump, record the odometer (Tank 0).
Drive normally for 2–3 tanks; always refill to first click at the same pump.
MPG = total miles ÷ total gallons across all tanks — averaging kills pump-click noise.
Cross-check with the trip computer; a persistent >10% gap means the computer needs calibration — or the car needs service.
Log with an OBD-II dongle for per-trip MPG if you want to isolate commute vs. highway behavior.

Practical Tips

•Learn your mi/kWh in winter and summer separately
•Derate fast-charge peak power by 20 to 30 percent for planning
•Charge at home overnight on the cheapest rate you can get
•Precondition the battery before fast charging in winter
•Track capacity at the same state of charge and temperature
•Add a charging stop margin on unfamiliar routes

Common Mistakes

Planning with peak charger power

Curves taper; use average power over your charge window.

Ignoring charging losses

Wall energy exceeds battery energy by 5 to 15 percent.

Using rated range for trips

Real highway range at speed with climate on runs below the rating.

Comparing sticker electricity prices only

Fees, idle fees and demand charges change the effective rate.

Assumptions

This calculator makes the following assumptions to provide estimates:

Average efficiency: One efficiency figure covers the whole window entered.

Average charge power: Taper curves are smoothed into the average used.

Usable capacity: Locked buffers are excluded from usable energy.

Limitations

Be aware of these limitations when using this calculator:

No battery thermal detail: Extreme heat or cold effects are averaged.

No tariff modelling: Complex time-of-use schedules are simplified to a blended rate.

No resale modelling: Degradation cost beyond replacement price is excluded.

Frequently Asked Questions

Answers to common questions about this calculator.

How is EV range calculated?

Multiply usable battery capacity in kWh by efficiency in distance per kWh. A 60 kWh usable pack at 3.5 mi/kWh yields 210 miles.

How long does charging take?

Divide energy to add by charger power times efficiency. Adding 40 kWh on a 7.4 kW home unit at 90 percent efficiency takes about 6 hours.

What do mi/kWh and kWh/100 km mean?

They are inverse efficiency views. Miles per kWh is distance per unit energy (higher better); kWh/100 km is energy per distance (lower better). Convert with 62.137 divided by mi/kWh.

What is charging efficiency?

The share of wall-plug energy that lands in the battery, typically 85 to 95 percent. Losses become heat in the charger, cable and battery.

What is usable versus gross battery capacity?

Gross is the physical pack; usable excludes top and bottom buffers the maker locks for longevity, often 5 to 10 percent.

How fast do EV batteries degrade?

Typically a few percent in year one then roughly 1 to 2 percent per year after, varying with heat, high states of charge and fast-charge frequency.

Is an EV cheaper per mile than gas?

Usually. At 3.5 mi/kWh and $0.15 per kWh the energy costs about 4.3 cents per mile versus 14 cents for a 25 MPG car at $3.50 per gallon.

When does an EV break even?

Divide the purchase premium over the gas alternative by yearly fuel plus maintenance savings. High-mileage drivers break even years sooner.

Should I fast-charge daily?

Occasional fast charging is fine; daily fast charging in heat accelerates degradation versus gentle home charging.

How is EV range calculated?

Multiply usable battery capacity in kWh by efficiency in distance per kWh. A 60 kWh usable pack at 3.5 mi/kWh yields 210 miles.

How long does charging take?

Divide energy to add by charger power times efficiency. Adding 40 kWh on a 7.4 kW home unit at 90 percent efficiency takes about 6 hours.

What do mi/kWh and kWh/100 km mean?

They are inverse efficiency views. Miles per kWh is distance per unit energy (higher better); kWh/100 km is energy per distance (lower better). Convert with 62.137 divided by mi/kWh.

What is charging efficiency?

The share of wall-plug energy that lands in the battery, typically 85 to 95 percent. Losses become heat in the charger, cable and battery.

What is usable versus gross battery capacity?

Gross is the physical pack; usable excludes top and bottom buffers the maker locks for longevity, often 5 to 10 percent.

How fast do EV batteries degrade?

Typically a few percent in year one then roughly 1 to 2 percent per year after, varying with heat, high states of charge and fast-charge frequency.

Is an EV cheaper per mile than gas?

Usually. At 3.5 mi/kWh and $0.15 per kWh the energy costs about 4.3 cents per mile versus 14 cents for a 25 MPG car at $3.50 per gallon.

When does an EV break even?

Divide the purchase premium over the gas alternative by yearly fuel plus maintenance savings. High-mileage drivers break even years sooner.

Should I fast-charge daily?

Occasional fast charging is fine; daily fast charging in heat accelerates degradation versus gentle home charging.

Related Calculators

Explore more calculators related to this topic.

Related Guides

Deepen your understanding with these educational resources.

Fuel-Efficient Driving Guide

Techniques that move real-world economy 10 to 20 percent

Maintenance Schedules

Service intervals that protect economy and range

Glossary

Technical terms used in mortgage calculations explained in plain language.

MPG: Miles per gallon. Distance travelled per gallon of fuel; higher is better. US gallon = 3.785 L.
L/100 km: Litres consumed per 100 kilometres; lower is better. Standard metric efficiency unit.
MPGe: Miles per gallon-equivalent. EV metric: miles travelled on 33.7 kWh (energy of 1 gal of gasoline).
CAFE: Corporate Average Fuel Economy — US fleet-average efficiency standard enforced by NHTSA.
Rolling resistance: Energy lost deforming tires as they roll. Low-pressure or wide tires raise it.
Aerodynamic drag: Air resistance growing with the square of speed — why highway MPG falls fast above 60 mph.
Hypermiling: Driving techniques (coasting, steady speed, anticipation) that maximise real-world MPG.
OBD-II: On-board diagnostics port. Scanners and dongles read live MPG, fuel trim and fault codes.
kWh: Kilowatt-hour: the billing unit of electric energy; 33.7 kWh holds the energy of a gallon of gas.
State of charge: Battery energy as a percent of usable capacity.

Authoritative References

Trusted sources and standards referenced by this calculator.

EPA — FuelEconomy.gov DOE — Fuel-Efficient Driving Tips NHTSA — Driving Safety & Efficiency SAE International — Fuel Economy Standards Consumer Reports — MPG Truth IRS — Standard Mileage Rates

Applicable Standards

EPA Fuel Economy Testing (40 CFR Part 600)CAFE — Corporate Average Fuel Economy Standards (NHTSA)WLTP — Worldwide Harmonised Light Vehicle Test ProcedureSAE J1321 / J1711 — Fuel consumption test proceduresISO 2575 — Road vehicles symbols & efficiency markings

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Page Information

Last Updated:

2026-09-24

Version:

2.0.0

References:

License:

Free to use for educational and professional purposes.

How you compare — vehicle class averages

Class	Combined MPG	City / Hwy	Fuel / 12k mi	Cost @ $3.50	CO₂ / yr
Compact sedan	34	30/40	353 gal	$1,235	3.1 t
Midsize SUV	25	22/29	480 gal	$1,680	4.3 t
Pickup truck	19	17/23	632 gal	$2,211	5.6 t
Hybrid sedan	49	50/47	245 gal	$857	2.2 t
EV (MPGe)	115	125/105	— (electric)	$550	1.1 t

Combined averages blend EPA city/highway cycles. EV row shows MPGe and home-charging cost; tailpipe CO₂ is zero, grid CO₂ ≈ 1.1 t/yr.

Maintenance checklist

Tick off what you already do — your car scores 1/6 (17%).