Math Tools
Free online math calculators and converters for business, science, and development. Calculate markup, convert scientific notation, and more — all running 100% in your browser.
Practical math utilities for the times when pulling up a spreadsheet is overkill. Markup Calculator handles the pricing math every small business eventually needs — markup percentage, profit margin, selling price, and the dreaded markup-vs-margin conversion (a 50% markup equals a 33.33% margin, not 50% — a confusion that costs unprepared sellers real money). Scientific Notation Converter bridges between the `6.022e23` form that appears in Python output, calculator apps, and physics papers and the decimal form you paste into Excel cells. Both tools show the formulas explicitly so you can understand the math, not just trust the answer.
Markup Calculator
Calculate markup percentage, profit margin, selling price, and profit — and convert between markup and margin instantly. Includes a reference table for common percentages and formulas explained.
Scientific Notation Converter
Convert numbers to and from scientific notation, E notation, and engineering notation. Includes a scientific notation calculator with step-by-step solutions.
The Math Tools Guide
Pricing: markup vs margin, explained
Markup is how much you add to your cost. Margin is how much of the selling price is profit. They describe the same transaction from different angles and they are not equal. A 100% markup (selling for double your cost) is a 50% margin. A 25% markup is a 20% margin. The formulas: Markup = (Sell − Cost) ÷ Cost, Margin = (Sell − Cost) ÷ Sell. For conversions: Markup = Margin ÷ (1 − Margin), Margin = Markup ÷ (1 + Markup). Sales teams and procurement usually talk in markup; finance and CFOs usually talk in margin. When a vendor says "30% margin" but you compute a 30% markup from their numbers, they've inflated the figure — the actual margin is only 23%. Run every vendor quote through the markup-margin converter before agreeing.
When scientific notation matters
Scientific notation shows up anywhere numbers span many orders of magnitude — astronomy (distances in parsecs), chemistry (Avogadro's number, 6.022 × 10²³), physics (Planck's constant), and software (floating-point representation, API rate limits, gigabyte-scale file sizes). Engineering notation is a variant where exponents are multiples of 3, aligning with SI prefixes (kilo 10³, mega 10⁶, giga 10⁹) — so 45,000,000 Hz reads as "45 MHz" rather than "4.5 × 10⁷". Use engineering notation when presenting to non-math audiences who read in units (electricians, network engineers, bandwidth specs); use scientific notation for academic and lab work.
Precision and IEEE 754 limits
Both tools run in the browser and use JavaScript's Number type, which follows the IEEE 754 double-precision standard. That gives you about 15-17 significant digits of precision — plenty for retail pricing, typical scientific calculations, and everyday engineering — but not enough for cryptocurrency amounts, high-precision crypto math, or arbitrary-precision science. If you're handling values above 2⁵³ (roughly 9 quadrillion) or require exact decimal arithmetic for financial regulatory work, use a BigDecimal library or server-side arbitrary-precision math. For 99% of pricing and science use cases, the browser's built-in precision is correct and fast.