Worked problems for every calculator

Basic Calculator

Perform quick addition, subtraction, multiplication, and division.

Scientific Calculator

Trig, logs, exponentials, and powers with degree/radian toggles.

Fraction Calculator

Operate on rational numbers with automatic simplification.

Percentage Calculator

Find parts, originals, raw percent values, or percentage change.

Discount & Final Price

Applies percentage discounts, quantity, and sales tax to show the true total.

Tip & Bill Split

Adds a gratuity and divides the check evenly across the party.

BMI Calculator (Metric)

Metric-friendly BMI with category classification.

Loan Calculator

Estimate monthly cost, total interest, and payoff for fixed-rate loans.

Mortgage Calculator

Principal & interest plus taxes, insurance, and HOA for home buyers.

Compound Interest Calculator

Project growth with recurring contributions and compounding frequency.

Retirement Calculator

Model retirement savings with monthly contributions and risk profiles.

Age Calculator

Compute exact age differences down to the day.

Date Calculator

Add/subtract days or measure distance between dates.

Time Calculator

Add or subtract HH:MM time spans with wrap-safe output.

Triangle Calculator

Solve triangle perimeter, area, and internal angles from three sides.

Quadratic Solver

Roots, discriminant, and root nature for quadratic equations.

Prime Factorization

Break integers into ordered prime factors.

LCM & GCF Calculator

Simultaneously get least common multiple and greatest common factor.

BMI Calculator (Imperial)

Feet/inches and pounds for BMI plus weight class insights.

Body Fat % (US Navy)

US Navy body-fat estimate with circumference measurements.

Body Surface Area Calculator

Computes Mosteller and Du Bois BSA with quick dosing hints.

Calorie Calculator

BMR, maintenance, cut, and bulk calories via Mifflin-St Jeor.

TDEE Calculator

Total daily energy expenditure from Mifflin-St Jeor BMR and activity multipliers.

Macro Split Planner

Turns daily calories into protein, carb, and fat gram targets using preset or custom ratios.

Calorie Deficit Planner

Shows the deficit, calorie target, and timeline needed to reach a goal weight.

Pregnancy Due Date

LMP-based due date with trimester milestones.

Water Intake Calculator

Daily hydration target from weight, workouts, climate, and life stage adjustments.

BMR (Mifflin-St Jeor)

Calculates basal metabolic rate from gender, weight, height, and age.

Heart Rate Zones Calculator

Maps recovery through VO₂ max zones using the Karvonen method.

Ideal Gas Law Calculator

Solves PV = nRT for any missing variable with Kelvin temperature.

pH ↔ [H⁺] Converter

Convert between pH and hydrogen ion concentration.

Molarity Calculator

Solves for molarity, moles, or volume in mol/L problems.

Dilution Calculator

C₁V₁ = C₂V₂ tool for stock and working solutions.

Cylinder Volume Calculator

Computes cylinder volume plus lateral and total surface area.

Circle Area Calculator

Calculates circle area and circumference from radius or diameter.

Sphere Volume Calculator

Finds the volume and surface area of a sphere from its radius.

Right Triangle Solver

Computes hypotenuse, area, perimeter, and angles from the two legs.

Polygon Area Calculator

Area, perimeter, apothem, and angles for any regular polygon.

Percentage Change Calculator

Computes percent difference between a starting and ending value.

Percentage Difference Calculator

Finds the percentage difference between any two measurements.

Polynomial Solver

Finds approximate roots (real or complex) for higher-degree polynomials.

System of Equations Solver

Solves linear systems using an augmented matrix.

Matrix Determinant Calculator

Computes determinants for square matrices up to 6×6.

Matrix Multiplication Calculator

Performs matrix multiplication when dimensions are compatible.

Eigenvalue Calculator

Finds eigenvalues and normalized eigenvectors for 2×2 matrices.

Vector Addition Calculator

Performs vector addition and subtraction component-wise.

Dot Product Calculator

Finds the scalar product plus the angle between vectors.

Cross Product Calculator

Computes the vector cross product in three dimensions.

Integral Calculator

Evaluates definite integrals and approximates antiderivatives.

Derivative Calculator

Computes first through fourth derivatives at a point.

Limits Calculator

Evaluates one-sided and two-sided limits numerically.

Partial Derivatives Calculator

Computes partial derivatives for functions of two variables.

Statistics Calculator

Finds mean, median, variance, and standard deviation for a dataset.

Variance Calculator

Calculates data variability around the mean as variance and standard deviation.

Standard Deviation Calculator

Computes σ, variance, range, and coefficient of variation from any dataset.

Probability Calculator

Computes event probabilities with percent, fraction, and odds outputs.

Z-Score & Percentile Calculator

Converts any raw score into a standardized z-value, percentile rank, and tail probability.

Mean Median Mode Calculator

Finds key measures of central tendency for a dataset.

Binomial Probability Calculator

Finds exact or cumulative probabilities for binomial experiments.

Normal Distribution Calculator

Evaluates z-scores and normal probabilities.

T-test Calculator

Performs Welch’s two-sample t-test with p-value.

ANOVA Calculator

Runs a one-way ANOVA across multiple groups.

Chi-Square Calculator

Computes the chi-square statistic and p-value for goodness of fit.

Conversion Calculator

Universal unit converter covering length, weight, temperature, and more.

Linear Regression Calculator

Fits a least-squares line, returns slope/intercept, and predicts any Y value.

Correlation Coefficient Calculator

Finds Pearson r, covariance, and standard deviations for paired samples.

Sample Size Calculator

Estimates the responses needed to hit a target margin of error and confidence level.

A/B Test Sample Size Calculator

Two-proportion power analysis for experiments with a target lift, confidence, and power.

Confidence Interval Calculator

Builds a two-sided z-interval around a sample mean.

Decimal to Fraction Converter

Converts decimals to equivalent fractions with simplification.

Fraction to Decimal Converter

Converts fractions to decimals quickly for calculations or spreadsheets.

Temperature Converter

Converts °C, °F, K, and °R with one input.

Weight/Mass Converter

Converts between kilograms, pounds, and ounces instantly.

Energy Converter

Swaps between joules, calories, and watt-hours in one view.

Power Converter

Converts Watts, kilowatts, megawatts, horsepower, and dBm.

Data Size Converter

Converts bytes among binary KB, MB, GB, and TB (plus bits).

Data Rate Converter

kbps, Mbps, Gbps, and MB/s conversions for throughput planning.

Currency Converter

Live-style currency conversions using configurable base rates.

Speed Converter

Converts between km/h, mph, and m/s.

Pressure Converter

Converts between bar, atm, psi, and pascal units.

Area Converter

Converts between square meters, square feet, acres, and hectares.

Volume Converter

Converts liters, cubic meters, US gallons, and US pints.

Length Converter

Converts between meters, feet, inches, yards, and miles.

Cooking Measurement Converter

Converts cups, spoons, ounces, grams, liters, and more kitchen-friendly units.

Time Zone Converter

Finds local time differences across global cities.

Interest Rate Calculator

Calculates effective annual rate and periodic interest from a nominal rate.

Salary Calculator

Converts annual pay into hourly, weekly, and monthly equivalents.

Tax Calculator

Estimates take-home pay using simple US, UK, or Canada tax brackets.

Investment Return Calculator

Computes ROI, absolute gain, and compound annual growth (CAGR).

ROI / ROAS Calculator

Blends ROI, ROAS, net profit, and annualized return for any campaign or capital project.

SIP Calculator

Projects SIP maturity, total contributions, and wealth gained over time.

Crypto Profit Calculator

Estimates crypto trade P&L after exchange fees, gas, and slippage.

Depreciation Calculator

Compares straight-line and declining-balance depreciation schedules.

Loan Amortization Calculator

Generates amortization schedules and payment breakdowns.

Currency Inflation Calculator

Adjusts money between years using an average inflation rate.

GST Calculator

Adds or removes Goods and Services Tax from any amount.

EMI Calculator

Finds the equated monthly installment for any fixed-rate loan.

Distance Calculator

Computes straight-line distance between two or three-dimensional points.

Fuel Cost Calculator

Estimates fuel needed, trip cost, and CO2 for road journeys.

Speed Distance Time Calculator

Solves the motion equation when any one variable is missing.

Force Calculator

Computes force from mass and acceleration (F = m·a).

Work Calculator

Finds mechanical work using force, displacement, and angle.

Power Calculator

Finds mechanical power or electrical power from multiple input combinations.

Projectile Motion

Range, time of flight, and peak height for a launch angle.

Free-Fall Calculator

Drop time and impact velocity from any height (no drag).

Ohm’s Law Calculator

Solves for voltage, current, or resistance in DC circuits.

Resistor Color Code Calculator

Decodes resistor band colors into resistance and tolerance.

Series/Parallel Resistors

Equivalent resistance calculator plus branch count at a glance.

Capacitance Calculator

Computes capacitance for parallel plate capacitors.

Inductance Calculator

Estimates inductance for air-core and ferrite-core coils.

Current Divider Calculator

Splits current through resistors in a parallel branch.

Voltage Divider Calculator

Computes output voltage for resistor dividers with load awareness.

Power Factor Calculator

Computes real, reactive, and apparent power with power factor.

RC Time Constant

Finds τ = R·C plus the time to hit 63%, 95%, and 99% charge levels.

dB Converter

Converts linear power or voltage ratios to decibels and back.

Electrical Power (P = VI)

Calculates real, apparent, and reactive power for single- or three-phase systems.

Permutation Combination Calculator

Computes nPr, nCr, and factorial values exactly.

Scientific Notation Calculator

Converts between standard numbers and scientific notation.

Logarithm Calculator

Computes logarithms in base 10, base e, or any custom base.

Exponential Growth Calculator

Models exponential change with initial value, rate, and time.

Heat Index Calculator

Outputs NOAA heat index, Celsius/Fahrenheit feels-like, and safety labels.

Wind Chill Calculator

Calculates wind chill and frostbite guidance from temperature plus wind speed.

GPA Calculator

Converts letter grades and credit hours into GPA and quality points.

Grade Calculator

Tracks assignment scores, current letter grade, and the score needed to hit a target.

Subnet Calculator

Breaks down IPv4 networks into mask, host range, broadcast, and host counts.

Sales Commission Calculator

Flat or tiered commission payouts based on total sales.

Break-Even Point

Calculates the units and revenue needed to cover fixed costs.

Markup ↔ Margin

Converts markup percentages to margins (and back).

Unit Economics (CAC:LTV)

LTV, CAC payback, and contribution per customer from ARPU, churn, and gross margin.

Runway & Burn Rate

Cash runway calculator with optional monthly burn increases.

SaaS MRR/ARR Dashboard

Tracks starting MRR, new bookings, expansion, churn, and contraction.

UTM Builder

Generates campaign tracking URLs with source, medium, term, and content.