Percentages, age, dates, units, tips, sales tax, discounts, margins, markup, and ROI in one calculator collection.
Calculate percentages, reverse percentages, and percent change.
Calculators
Calculate exact age in years, months, and days from a birth date.
Calculators
Find the difference between two dates in days, weeks, and more.
Calculators
Convert length, weight, and temperature units instantly in your browser.
Calculators
Split the bill with tip percentage and per-person totals instantly.
Business Tools
Add sales tax to a pre-tax amount and see tax plus total due.
Business Tools
Compute sale price, savings, and optional tax from a discount %.
Business Tools
Calculate profit, margin %, and markup from cost and revenue.
Business Tools
Set a markup % on cost to get selling price and implied margin.
Business Tools
Measure return on investment from cost and total return.
Business Tools