Math & Money Tools
Percentages, increases, decreases and ratios in a single click. Quick everyday maths, solved in seconds — right in your browser, no sign-up.
Everyday maths, done properly
The tools in this category are the ones people reach for mid-decision: a loan offer on the table, a price to set, a discount that looks too good. The Loan Calculator is the heavyweight — enter an amount, an APR and a term and you get the monthly payment, the total interest and a first-year amortization table showing where each payment actually goes.
For pricing, the pair to know is the Profit Margin Calculator and the Markup Calculator: margin and markup are different numbers built from the same cost, and confusing them is one of the most common small-business pricing mistakes. The Percentage Calculator handles the rest — increases, decreases and "what percent is X of Y" — in one click.
Guides from the blog
- How to Calculate Profit Margin: Margin vs Markup With Worked Examples — Cost vs selling price divided two ways — $80 to $100 is a 20% margin and a 25% markup — plus the $1,428.57 price a true 30% margin requires.
- How to Calculate a Discount — Sale prices, savings, and why stacked discounts are not what they seem.
- How to Calculate Percentages — The three formulas behind every percent question.
- How to Calculate Loan Payments — A $25,000 loan worked in full, month by month.
- Compound Interest with Monthly Contributions: How It Really Grows — Why monthly deposits beat lump sums for most savers — the rule of 72 and a $500/month worked example.