Calculators

Pick the 4 band colors on a resistor to read its resistance and tolerance.

Project your retirement savings from current savings and monthly contributions. Free, in your browser, no sign-up.

Hypotenuse, angles, area from two legs. Free, instant, in your browser.

Work out your required minimum distribution from an IRA or 401(k) for this year, using the IRS Uniform Lifetime Table and last year-end balance. Free, in your browser, no sign-up.

Calculate return on investment from the amount invested and returned. Free, in your browser, no sign-up.

Calculate return on invested capital (ROIC) from operating income, tax rate, debt, equity and cash. Free, in your browser, no sign-up.

Roof pitch, angle and slope from rise and run. Free, instant, in your browser.

Roof squares and shingle bundles. Free, instant, in your browser.

Project a Roth IRA balance at retirement from your current balance, yearly contributions and expected return, all growing tax-free. Free, in your browser, no sign-up.

Round to decimals or tens, up or down. Free, instant, in your browser.

Work out the monthly payment and total interest on a loan for an RV, motorhome, camper or travel trailer. Free, in your browser, no sign-up.

Convert any pay amount between annual, monthly, semi-monthly, biweekly, weekly, daily and hourly figures in one step. Free, in your browser, no sign-up.

See your new salary after a percentage raise, and the difference per year, per month and per hour. Free, in your browser, no sign-up.

Add sales tax to an amount and see the tax and total. Free, in your browser, no sign-up.

Survey sample size for a margin of error. Free, instant, in your browser.

Sand in cubic yards, tons and bags. Free, instant, in your browser.

Project a savings balance from an initial deposit, monthly contributions and the account APY. Free, in your browser, no sign-up.

Work out how much to save each month to reach a savings goal by a set date, counting what you already have and the interest it earns. Free, in your browser, no sign-up.

Model and map scale conversions. Free, instant, in your browser.

A full scientific calculator with trig, logs, powers, roots, and factorials, evaluated safely. Free, in your browser, nothing is uploaded.

Standard ↔ scientific and E notation. Free, instant, in your browser.

Estimate what a monthly SIP in mutual funds grows to, with an optional yearly step-up, split into amount invested and estimated returns. Free, in your browser, no sign-up.

Find the best bedtimes or wake times based on 90-minute sleep cycles. Free, in your browser, nothing is uploaded.

Slope, equation and distance of a line. Free, instant, in your browser.