Area Calculator — Square Feet, Shapes, Rooms & Land

Calculate square footage for shapes, rooms, walls, roofs, and irregular land; include cutouts, waste, packages, cost, formulas, and diagrams.

Alcohol Dilution Calculator — Blend ABV & Convert Proof

See how much water or a second liquid to add, build a target batch, convert ABV and U.S. proof, and check common 40% dilution answers.

Volume Calculator — Cubic Feet, Gallons, Tanks & Materials

Calculate shapes, tanks, pools, materials, missing dimensions, or convert cubic feet, cubic yards, gallons, liters, and cubic meters.

Grade Calculator — Weighted Grades, Final Exam & GPA

Calculate weighted course grades, final exam targets, semester and cumulative GPA, or the GPA needed to reach a goal.

Age Calculator — Exact Age, Days & Next Birthday

Calculate exact calendar age in years, months and days, total elapsed days, hours and minutes, age on any date, and the next birthday.

Free Date Calculator — Days Between Dates & Age Calculator

Calculate days between dates, add or subtract days, or find an exact age with weekend controls, clear steps, and instant visual results.

Time Calculator — Hours, Duration & Timesheet

Add or subtract time, find hours between clocks, total timesheet shifts and pay, or convert duration units with clear visual results.

Tip Calculator — Tax, Split Bill & Custom Shares

Calculate restaurant tips before or after tax, split the bill equally or by custom shares, round the total, and see exactly what each person pays.