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Business10 calculators

Business

Break-Even Point Calculator

Units & revenue needed to cover fixed costs.

Customer LTV

Gross-profit CLV plus optional CAC payback and LTV:CAC from your own averages.

EOQ Calculator

EOQ, ordering cadence, and annual cost balance for recurring inventory orders.

Inventory Turnover

Turnover ratio, days on hand, and daily COGS burn from your own period totals.

Markup & Margin Calculator

Find profit, markup %, and margin % from cost and price

Payback Period Calculator

Time to recover an up-front business spend.

Reorder Point Calculator

Reorder threshold, reorder timing, and stockout timing from your own assumptions.

ROI Calculator

ROI %, annualized rate, and simple payback in years.

Staffing Requirements Calculator

Estimate FTE and headcount from workload.

VAT / Sales Tax Calculator

Add or remove VAT/sales tax — net, tax & gross breakdown.

Construction & DIY12 calculators

Construction & DIY

Brick Wall Calculator

Estimate bricks and mortar for a wall after openings, joints, thickness, and waste.

Concrete Calculator

Volume and bag count for slabs and columns.

Decking Calculator

Estimate deck boards, rows, and stock-board count before buying.

Drywall Calculator

Estimate drywall sheets needed for any room.

Fence Estimator

Panels and posts for a straight run or rectangular yard.

Insulation Calculator

Plan insulation packages from area, openings, waste, and pack coverage.

Mulch & Gravel Calculator

Volume of mulch or gravel for any area.

Paint Calculator

Estimate paint quantity for any room.

Roof Pitch Calculator

Roof-side geometry planner with x:12 pitch and rafter length.

Stair Calculator

Plan a straight-stair layout from rise and tread dimensions.

Tile Estimator

Estimate tiles needed for any floor or wall area.

Wallpaper Calculator

Rolls to buy for any rectangular room.

Date & Time28 calculators

Date & Time

Age Calculator

Exact age from birth date to today.

Birthday Countdown

How many days until your birthday.

Chinese Zodiac Calculator

Chinese zodiac animal from your birth date.

Date Add/Subtract Calculator

Exact calendar date after adding or subtracting mixed offsets.

Date Difference Calculator

Exact time span between any two dates.

Day of Week Calculator

Find the weekday for one calendar date.

Day Progress

How much of today is over, ticking live.

Days Until a Date Calculator

How many days until any date.

Days until Christmas

Count the days and full weeks left until 25 December.

Days until Easter

Count days and full weeks to Western Easter Sunday.

Days until Halloween

Count the days and full weeks left until 31 October.

Days until New Year

Count the days and full weeks left until 1 January.

Days Until Retirement Calculator

Time until retirement using your chosen age assumption.

Days until Thanksgiving

Count days and full weeks to U.S. Thanksgiving.

Days until Valentine’s

Count the days and full weeks left until 14 February.

Hours Between Calculator

Hours between two dates and times.

ISO Week Number Calculator

Find the ISO week label and Monday-to-Sunday bounds for one date.

Life in Weeks Calculator

Your planning horizon, one square per week.

Month Progress

How much of the month is over.

Nth Weekday of Month Calculator

Find the nth chosen weekday inside one or more Gregorian months.

Paydays Left

How many paydays are left this year.

Quarter Progress

How much of the calendar quarter is over.

Weekdays Calculator

Weekdays between two dates.

Weekends Left

How many weekends are left this year.

Week Progress

How much of the week is over.

Workday Progress

How much of the workday is over, ticking live.

Year Progress Calculator

How much of the year is over today.

Zodiac Sign Calculator

Western zodiac sign from your birth date.

Everyday Costs9 calculators

Everyday Costs

Discount Calculator

Final price and savings from a percent-off or fixed-amount discount.

Driving Cost Calculator

Fuel cost for commutes, errands, and trips.

Electricity Cost Calculator

Cost of running a device from watts and hours.

Final Grade Calculator

Required final score and what-if overall grade on one shared scale.

Fuel Efficiency Calculator

Real fuel economy from distance and fuel used.

Recipe Scaler

Resize a full recipe by servings.

Split Bill Calculator

Split a bill evenly with optional tip.

Tip Calculator

Calculate tips and split bills between people.

Unit Price Comparison

Cheapest per unit, up to five packs.

Geometry14 calculators

Geometry

Arc Length Calculator

Solve one circle sector from radius and central angle.

Aspect Ratio Calculator

Resize an image or video to a new width or height without changing its shape.

Circle Calculator

Find the area, circumference, diameter, or radius of a circle from any one value.

Oval Area Calculator

Exact ellipse area plus an honest edging-length estimate from two oval measurements.

Parallelogram Solver

Area, diagonals, height, and angle pair from base + side + height or angle.

Polygon Area by Coordinates

Area and perimeter from ordered polygon coordinates.

Pythagorean Theorem Calculator

Find the missing side of any right triangle.

Rectangle Calculator

Area, perimeter, diagonal, and missing-side solving for any rectangle or square.

Regular Polygon Calculator

Solve any regular polygon from side, apothem, radius, perimeter, or area.

Screen Size Calculator

Real width, height, and area from diagonal + ratio.

Trapezoid Calculator

Area, height, midline, perimeter, and isosceles-diagonal solving.

Triangle Solver

Area, perimeter & angles from three sides.

Two-Point Distance

Find the straight-line distance and midpoint between two coordinates.

Volume Calculator

Volume of five common shapes, with liquid capacity.

Health & Fitness14 calculators

Health & Fitness

BMI Calculator

Calculate your BMI from weight and height.

Body Fat Calculator

Estimate body fat % from circumference measurements

Calorie Calculator

Daily calorie target for cut, maintain, or bulk goals.

Goal Weight Timeline Calculator

Estimate when a weight goal could land at a chosen weekly pace.

Heart Rate Zones Calculator

Find your 5 heart rate training zones

Macros Calculator

Daily protein, carbs, and fat grams from your calorie target.

One-Rep Max Calculator

Estimate your 1RM from a working set.

Ovulation Calculator

Ovulation & fertile window estimator.

Pregnancy Due Date Calculator

Estimated due date from your last period.

Race Time Predictor

Predict a race time from a known performance.

Running Pace Calculator

Compute pace, time, or distance for a run.

Sleep Cycle Calculator

Bedtimes or wake-ups aligned to 90-minute cycles.

VO2 Max Calculator

Estimate VO2 max from a 12-minute or 1.5-mile run test.

Water Intake Calculator

Estimate a daily water baseline

Mathematics21 calculators

Mathematics

Arithmetic & Geometric Sequences

Nth term and finite sum for arithmetic or geometric sequences

Binomial Probability

Exact and cumulative binomial probabilities

Confidence Interval

Mean and proportion confidence intervals from sample summaries

Cubic Equation Calculator

Solve cubic equations and classify the root pattern

Derivative Calculator

Differentiate an expression symbolically

Fraction Calculator

Add, subtract, multiply, or divide fractions

GCD & LCM Calculator

Find GCD and LCM of two numbers

Linear Equation Grapher

Graph y = mx + b with intercepts

Linear Regression

Fit a straight line, inspect r and R², and estimate y

Linear System Solver

Solve two simultaneous linear equations

Matrix Calculator

Small-matrix add, multiply, determinant, inverse, and transpose

Normal Distribution

Below, above, between, and percentile cutoffs for a normal model

Percentage Calculator

Three-mode percentage calculator

Permutations & Combinations

Exact counts for the four standard combinatorics cases

Polynomial Division Calculator

Exact quotient and remainder for polynomial long division

Prime Factorization Calculator

Find prime factors of any integer

Quadratic Equation Solver

Solve ax² + bx + c = 0 with roots and vertex

Scientific Calculator

Evaluate math expressions with advanced functions

Statistics Calculator

Mean, median, mode, std dev from a data set

Survey Sample Size

Plan a response target for survey proportions.

Weighted Average Calculator

Weighted mean from percent or raw weights.

Personal Finance19 calculators

Personal Finance

CAGR Calculator

Annualized growth rate from start, end, and years.

Compound Interest Calculator

Lump-sum growth over time, with optional monthly top-ups.

DCA Investment Calculator

Future value of monthly contributions.

Debt Payoff Calculator

Time to pay off debt, total interest & months saved with extra payments.

Debt-to-Income Ratio Calculator

Current DTI, with-new-payment DTI, and optional planning room.

Emergency Fund

Plan a cash reserve target from your own monthly essentials and chosen coverage months.

Hourly Wage to Annual Salary Calculator

Hourly rate to yearly salary, both ways.

Inflation Calculator

Past money in today's purchasing power.

Loan Calculator

General loan / car / personal — monthly payment, interest & early payoff.

Mortgage Calculator

Full PITI monthly payment in one number.

Net Worth

Current balance-sheet snapshot from your assets, debts, and estimated values.

Portfolio Rebalancing

Buy/sell plan for bringing holdings back toward a target allocation.

Refinance Break-Even Calculator

Months until refi savings repay closing costs.

Rent vs. Buy Calculator

Which path leaves you ahead after your planned stay?

Retirement Calculator

Estimate your retirement nest egg from current savings, contributions & returns.

Savings Goal Calculator

Monthly savings needed to reach your goal, accounting for returns.

Savings Withdrawal Calculator

Runway, depletion timing, and target-horizon balance from your assumptions.

Subscription Break-Even Calculator

When a subscription model pays back setup and monthly costs.

Time Value of Money Calculator

Future value, present value, or payment for periodic cash flows.

Science23 calculators

Science

Beer-Lambert Law Calculator

Solve concentration, absorbance, path length, or molar absorptivity from A = εcl

Bernoulli Equation Calculator

Estimate one missing Bernoulli variable between two points

Buoyancy Calculator

Float/sink verdict, submerged fraction, and load margin from displacement volume

Centripetal Force

Solve force, acceleration, speed, or radius for circular motion

Density Calculator

Compute density, mass, or volume from two known values

Free Fall

Solve 1D vertical drop and throw timing without hand-solving the quadratic

Hydrostatic Pressure Calculator

Find hydrostatic gauge pressure or absolute pressure from liquid depth

Ideal Gas Law Calculator

Solve any one of P, V, T, or n from the other three

Kinematics

Solve 1D constant-acceleration motion

Kinetic Energy Calculator

Compute KE = 1/2 mv² from mass and velocity

Molarity Calculator

Prep-focused molarity math from amount and final solution volume

Ohm's Law Calculator

Solve for V, I, or R with Ohm's Law

pH and pOH

Turn pH, pOH, [H3O+], or [OH-] into the full matching set.

Photon Energy

Turn wavelength, frequency, or photon energy into the other two.

Pipe Reynolds Number

Reynolds number and likely pipe-flow regime from velocity or flow rate

Potential Energy Calculator

Compute PE = mgh from mass, gravity, and height

Projectile Motion Calculator

Compute range, max height, and flight time for projectiles

Serial Dilution

Tube-by-tube serial dilution plan with repeated steps, exact final landing, and transfer-volume warnings

Snell's Law Calculator

Predict refraction, critical angle, and total internal reflection

Solution Dilution Calculator

Stock volume, solvent top-up, and dilution factor in one basis

Speed, Distance & Time Calculator

Compute speed, distance, or time from two known values

Terminal Velocity Calculator

Solve steady-state fall speed from mass, drag, area, density, and gravity

Voltage Divider

Check or size a loaded two-resistor divider.

Unit Conversion16 calculators

Unit Conversion

Angle Converter

Convert exact angle units only.

Area Converter

Convert square units, acres, and hectares without drifting into estimating.

Cooking Measurements Converter

Convert cups, tablespoons, ounces and more for cooking.

Energy Converter

Convert one energy value between common energy units.

File Size Converter

Convert bytes, KB/MB/GB, and KiB/MiB/GiB with the right base every time.

Flow Rate Converter

Convert pump, faucet, and airflow flow-rate units.

Length Converter

Convert metric and imperial length units without cross-category noise.

Power Converter

Convert one power rating between common spec-sheet units.

Pressure Converter

Convert one pressure reading between common gauge, lab, and barometer units.

Speed Converter

Convert one speed value between common speed units.

Temperature Converter

Convert temperatures with dedicated Celsius, Fahrenheit, and Kelvin controls.

Time Unit Converter

Convert fixed duration units only.

Torque Unit Converter

Convert torque units for wrench settings and spec comparisons only.

Transfer Rate

Convert Mbps, MB/s, and GiB/s through a clear b/s base.

Volume Converter

Convert liters, gallons, cups, and cubic units.

Weight Converter

Convert weight and mass units with a focused metric-to-imperial tool.

Calculate anything. Keep it focused.simple.