Start with the question
Every calculator begins with a specific task and a research record. We document the inputs, units, formula, sources, assumptions, and examples before implementing it. Tools that answer the same question should share one useful page.
Keep time arithmetic exact
Clock times are represented as whole minutes. Hours and minutes are converted to decimal hours only when needed for a displayed result or pay calculation. For example, 7 hours and 30 minutes is 450 minutes, or 7.5 hours—not 7.30 hours.
Make assumptions visible
Overnight shifts, unpaid breaks, weekly thresholds, and overtime multipliers need explicit treatment. A calculator must explain how it interprets them. A default value is an editable assumption, not a statement about the rule that applies to your employment.
Separate estimates from payroll
Gross pay is an amount before taxes and other deductions. An estimate based on entered hours and rates does not determine take-home pay or establish a legal entitlement.
Test the edges
Before release, each calculator needs at least eight documented test cases as well as boundary checks. These include empty values, zero, invalid numbers, rounding, overnight times, and breaks longer than a shift where relevant.
Review the complete experience
Formula tests are only part of the review. Labels, keyboard access, mobile input, result announcements, copying, and printing must also work. Sources and assumptions belong beside the tool so you can check the reasoning yourself.
See it in practice
The time card calculator shows minute-based arithmetic, overnight shifts, and daily-then-weekly overtime. The biweekly pay calculator shows why overtime is counted per workweek. Our guides, such as how overtime pay is calculated, work every example by hand and link to their sources.
Every calculator listed on the calculators page with a link has completed this process. Tools shown there without a link are still in research.