How to calculate your real MPG properly
A practical UK guide to measuring real imperial MPG using the full-to-full method, with formulas, worked examples and a fill-up log.
Read guide →Motoring guides
Calculations you can follow, not filler around a tool
These guides start with a real motoring question, show the units and arithmetic, work through examples and then link to the calculator that lets you use your own figures.
1Understand the measure
2Follow a worked example
3Run your own scenario
UK MPG, US MPG and L/100km explained
Understand UK imperial MPG, US MPG and litres per 100 km, with conversion formulas and a practical comparison table.
Read guide →How to calculate fuel cost per mile and journey cost
Calculate fuel cost per mile and journey fuel cost from UK MPG, fuel price and distance, with worked examples and a sensitivity table.
Read guide →How much does it cost to charge an EV at home?
Calculate home EV charging cost from battery percentage, tariff and charging efficiency, with wall-energy calculations and a UK p/kWh table.
Read guide →How to compare an EV tariff properly
A practical guide to comparing EV and standard electricity tariffs using whole-house annual cost, peak/off-peak use, standing charges and EV mileage.
Read guide →Home vs public EV charging: compare the real energy cost
Compare home, off-peak and public EV charging fairly using p/kWh, charging efficiency, mixed charging and membership break-even calculations.
Read guide →How to compare the real running cost of two cars
A structured way to compare annual car running cost including fuel or electricity, tax, insurance, servicing, tyres and depreciation.
Read guide →Should I keep my car or change it? The numbers to compare
A practical framework for comparing the financial cost of keeping a current car versus changing vehicle, including depreciation, running costs and change costs.
Read guide →Tyre sizes explained: width, profile, wheel and rolling diameter
Understand tyre width, profile and wheel diameter, calculate overall tyre diameter and circumference, and see how size changes affect gearing and indicated speed.
Read guide →BHP, HP, PS and kW explained
Understand BHP, mechanical horsepower, metric PS and kilowatts, with exact conversion relationships, a reference table and power-to-weight examples.
Read guide →What belongs in a MotoringCalcs guide?
A guide should answer a question that is useful even before you touch the calculator. We show the calculation where it can be stated clearly, distinguish exact conversions from assumptions, and avoid presenting generic estimates as vehicle-specific facts. Manufacturer specifications, measured vehicle data and current tariff terms should replace generic assumptions whenever they are available.