Guides
Short, practical explanations to go with the calculators: how loans and APR work, how much paint or flooring to buy, and how to budget a road trip.
How loan interest worksHow monthly loan interest is calculated, why early payments are mostly interest, and how term length and extra payments change the total cost.APR vs interest rateThe difference between a loan interest rate and APR, how fees raise the true cost of borrowing, and how to compare loan offers fairly.How much paint do you need for a room?Gallons of paint for common room sizes, how to measure walls, how many coats you need and when to buy primer, with a quick reference table.How to measure a room for flooring, tile and paintMeasure square footage accurately for flooring, tile and paint, including L-shaped rooms, closets, unit conversions and waste allowances.How to budget fuel for a road tripWork out a road trip fuel budget in litres or gallons, convert L/100 km and MPG, and split the cost between passengers, with worked examples.
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Reviewed October 2026 · How we build our calculators · Report an issue