Math Calculators

Pinewood Derby Car Speed & Weight Calculator

Get your car's track speed, mph, and scale speed from distance and time, plus front/rear axle weight split against the 5oz limit. Free, instant.

Pizza Size & Value Comparison Calculator

Compare up to 4 pizzas by true price per square inch and cost per slice to see which size is actually the better deal. Free, instant, no sign-up.

Turkey (Holiday Roast) Cooking Time & Temperature Calculator

Calculate exactly how long to cook a turkey by weight, stuffed or unstuffed, oven temperature, and roasting method (conventional, convection, or spatchcock). Free, instant.

Aspect Ratio Calculator

Simplify a width:height ratio (e.g. 1920x1080 to 16:9) or solve for a missing dimension from a target ratio. Free tool for video, photo, and design.

Depth of Field & Hyperfocal Distance Calculator

Calculate hyperfocal distance and the near/far limits of acceptable sharpness from focal length, aperture, subject distance, and sensor format. Free, instant.

Pythagorean Theorem Calculator

Calculate any side of a right triangle using the Pythagorean theorem. Solve for hypotenuse, base, or height instantly.

Mean Median Mode Calculator

Calculate mean, median, mode, range, and standard deviation from any set of numbers. Free statistics calculator.

Square Root Calculator

Calculate square roots, cube roots, and nth roots. Shows simplified radical form (e.g. 6√2) and detects perfect squares.

Surface Area Calculator

Calculate surface area of 6 shapes: sphere, cube, cylinder, cone, rectangular prism, and square pyramid. Step-by-step solutions.

Decimal to Fraction Converter

Convert any decimal to a simplified fraction in lowest terms. Shows mixed number, GCD steps, and fraction check.

Age Calculator

Calculate exact age between two dates. Shows years, months, days, total weeks, hours, and next birthday countdown.

Biorhythm Calculator

Free biorhythm calculator. Enter your birth date to chart your physical (23-day), emotional (28-day), and intellectual (33-day) cycles and see upcoming critical days.

Sudoku Solver

Solve any 9x9 Sudoku puzzle instantly in your browser. Type digits into the grid or paste a puzzle string, plus a built-in validator to check for conflicts.

Darts Checkout Calculator

Enter your remaining darts score (2-170) for the best 1, 2, or 3-dart checkout route ending on a double. Flags bogey numbers with a setup-shot suggestion. Free, instant.

Garden Plant Spacing Calculator

Enter your garden bed size to see how many plants fit in a grid or offset layout, or switch to Square Foot Gardening mode. 40+ preset vegetables and herbs. Free, instant.

Home Backup Generator Sizing Calculator

Check off the appliances you need during an outage to get the minimum generator wattage required, plus which common generator sizes (2000W-20000W+) can cover your load. Free, instant.

Fantasy Football Points Calculator

Enter a player’s stat line and get instant fantasy points under Standard, Half-PPR, PPR, or fully custom league scoring rules — with a full points breakdown.