This guide explains the core arithmetic behind the tools. It is intended to help you check assumptions and understand your own pay records, not to provide jurisdiction-specific legal advice.
Understand the components
An overtime calculation starts with three numbers: your base hourly wage, the hours eligible for a higher rate, and the applicable multiplier. A multiplier of 1.5 means each qualifying hour earns 150% of your usual wage; 2.0 means 200%.
Keep regular hours separate
Multiply non-overtime hours by the normal hourly rate. Multiply overtime hours by the rate and multiplier. Add the two amounts for gross earnings. For example, a worker earns $18 per hour for 40 regular hours and 6 overtime hours at 1.5×. The regular portion is $720, the overtime portion is $162, and the combined gross amount is $882.
Check which rule applies
A 1.5× multiplier is common, but not universal. Workweek definitions, eligibility and the treatment of bonuses or shift differentials vary across countries and agreements. Consult your contract, payroll policy or the appropriate local source rather than assuming an overtime rate.
Avoid mixing gross and net
An overtime calculator gives gross earnings. Taxes and deductions are separate. If you estimate take-home pay, clearly separate assumptions from known values and check the actual payroll statement.