Helpful Guides

A simple guide to percentage formulas with practical examples for shopping, bills and everyday calculations.

Learn how to calculate the discount amount, final price and total savings from a sale price.

Understand how to add VAT, remove VAT and calculate the tax amount from a total price.

Learn how watts, hours, days and kWh price affect your electricity bill.

Estimate trip fuel cost from distance, fuel consumption and fuel price.

Understand the difference between megabits per second and megabytes per second when downloading files.

Calculate work time between start and end hours, including breaks and weekly totals.

Find age in years, months and days using a date of birth and another date.

Learn how money grows when interest is added to the balance over time.

Understand revenue, cost, profit and margin percentage for a product or service.

Calculate room area for flooring, paint planning and home improvement estimates.

Compare products by unit price to see which option is actually cheaper.

Learn the basic idea behind monthly loan payments, interest and repayment terms.

Organize income, fixed costs, variable expenses and savings goals in one monthly plan.

Quickly calculate tip amount, final bill and split amount per person.

Understand markup percentage and how it differs from profit margin.

Find how many units you need to sell to cover fixed and variable costs.

Count weekdays between dates and understand when weekends are excluded.

Estimate file download time using file size and internet speed.

Estimate how much data streaming, browsing, downloads and cloud backups use.

Estimate how much an air conditioner costs to run based on power, hours and electricity rate.

Estimate water use from showers, taps, washing machines and daily routines.

Estimate electric vehicle charging cost from battery size, charge percentage and electricity rate.

Calculate return on investment and understand profit compared with original cost.

Calculate the percentage of visitors who complete a desired action.

Estimate percentage and fixed payment fees before receiving the net amount.

Convert between KB, MB, GB and TB for downloads, storage and backups.

Resize images or videos while keeping the same proportions.

Estimate daily, weekly and monthly screen time from device use.

Estimate overtime earnings from hourly rate, overtime multiplier and extra hours.

Compare equal rent split and room-size based rent split methods.