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80+ Free Calculators & Tools
Run secure, client-side financial solvers, health trackers, math graphing pads, and unit converters instantly in your local browser sandbox.
Finance & Loans
Online Mortgage & Home Loan Payment Calculator
Calculate monthly mortgage payments, property taxes, home insurance, PMI, and HOA fees. View interactive payment schedules and principal reduction breakdown.
Auto & Car Payment Loan Calculator
Calculate monthly car payments, total loan interest, trade-in value credit, sales tax, and dealer fees for new or used vehicles.
Personal Loan Interest & Payoff Calculator
Free personal loan payment calculator. Estimate fixed monthly paydowns, cumulative interest expenses, and loan payoff acceleration.
Salary & Net Take-Home Paycheck Calculator
Calculate net take-home pay, federal income tax, state taxes, FICA (Social Security & Medicare), and 401(k) retirement withholdings.
401(k) & Roth IRA Nest Egg Calculator
Project future retirement wealth, employer 401(k) match contributions, Roth vs Traditional tax advantages, and inflation-adjusted purchasing power.
Compound Interest & Fixed Yield CD Calculator
Calculate compound interest growth over time with recurring deposits, CD APY yields, and inflation impact.
Profit Margin, Markup & Tip Calculator
Calculate net profit margin percentage, gross markup on cost, restaurant tip percentages, and split dining bills evenly.
Refinance & Home Equity HELOC Payment Calculator
Compare cash-out refinance vs HELOC line of credit, new interest rates, closing costs, break-even months, and monthly mortgage savings.
Credit Card Payoff & Interest Reduction Calculator
Calculate how long to pay off credit card balance, interest saved with snowball vs avalanche methods, and monthly payoff targets.
Student Loan Repayment & Interest Calculator
Analyze federal and private student loan repayment options, Income-Driven Repayment (IDR/SAVE), extra principal payoff, and interest totals.
Business Loan, ROI & Compound Annual Growth Calculator
Calculate business loan amortization, Return on Investment (ROI), Compound Annual Growth Rate (CAGR), and net profit margins.
Social Security Retirement Benefit Estimator
Estimate monthly Social Security retirement benefits by claiming age (62 early, 67 Full Retirement Age, 70 delayed), inflation COLA, and salary history.
Debt-to-Income (DTI) Ratio Calculator
Calculate front-end (28%) housing DTI and back-end (36%) total debt DTI ratios required for mortgage approval.
Commercial Mortgage, Bond & Construction Loan Calculator
Calculate commercial property loans, bond yields, construction drawdown schedules, LTV ratios, and down payments.
Mortgage Borrowing Power & Rental Yield Calculator
Calculate maximum home loan borrowing capacity based on income & expenses, plus rental yield % for buy-to-let investment properties.
Term Deposit, Gold Loan & Forex Compounding Calculator
Calculate CD / term deposit fixed interest, gold collateral loan payments, and compounding growth for forex & share investments.
Inflation & Purchasing Power Calculator
Calculate purchasing power loss, historical inflation adjustment, and future price level projections.
VAT & Sales Tax Calculator
Add or remove Value Added Tax (VAT) and sales tax to find net price, gross total, and tax amount.
Car & Vehicle Depreciation Calculator
Estimate vehicle value decline over 1 to 10 years based on mileage, initial price, and depreciation rate.
Simple Interest Calculator
Calculate simple interest earned or owed using Principal × Rate × Time formula.
Health & Body
Body Mass Index (BMI) & Health Category Calculator
Calculate Body Mass Index (BMI) accurately. View CDC official health category ranges (Underweight, Normal, Overweight, Obese) and target healthy weight bounds.
BMR & Total Daily Energy Expenditure (TDEE) Calculator
Calculate Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE) using the Mifflin-St Jeor formula for calorie burning.
Calorie Deficit & Target Weight Loss Calculator
Calculate daily calorie intake for healthy weight loss (1-2 lbs per week), maintenance calories, and target weight reach dates.
Macronutrient & Calorie Split Calculator
Calculate exact daily protein, carbohydrate, and fat gram targets tailored for muscle gain, keto, or body recomposition.
Bra Size Band & Cup Measurement Calculator
Accurate bra size calculator using underbust band and bust measurements. Converts US, UK, and EU cup & band sizes.
Mid-Parental Child Adult Height Predictor
Predict child adult height using the mid-parental height method and parental genetics.
US Navy Body Fat Percentage Calculator
Calculate body fat percentage, lean body mass, and fat mass using US Navy neck, waist, height, and hip circumference measurements.
Ideal Body Weight & Hydration Intake Calculator
Find ideal body weight (IBW) target ranges using Devine & Miller equations, and calculate recommended daily water hydration in liters and ounces.
Daily Water Intake & Hydration Calculator
Calculate recommended daily water intake in liters and cups based on body weight, climate, and exercise level.
Target Heart Rate & Training Zone Calculator
Calculate fat burn, aerobic, and anaerobic heart rate zones using age and resting heart rate (Karvonen method).
Body Surface Area (BSA) Calculator
Calculate medical Body Surface Area in m² using Mosteller, Du Bois, and Gehan-George formulas.
Math & Graphing
TI-84 & Desmos Online Graphing Scientific Calculator
Free online TI-84 Plus CE & Desmos style scientific graphing calculator. Plot mathematical functions, roots, trigonometry, exponents, and equations on an interactive canvas.
Step-by-Step Math Formula & Algebra Solver
Step-by-step math problem solver for quadratic equations ax²+bx+c=0, distance formula, slope between points, and factoring.
Fraction & Percentage Change Calculator
Calculate fraction arithmetic (+, -, ×, ÷), percentage increase, decrease, percentage difference, and fraction to decimal conversions.
Cumulative GPA & Target Grade Calculator
Calculate high school and college unweighted 4.0 and AP/Honors weighted 5.0 GPA, target cumulative semester goals, and final exam required grades.
Statistics Summary & Matrix Algebra Solver
Calculate mean, median, mode, sample standard deviation, variance, matrix multiplication (A × B), determinant, and linear algebra solutions.
2D & 3D Geometry Area, Volume & Perimeter Calculator
Calculate area, surface area, volume, and perimeter for triangles, circles, cylinders, spheres, and polygons.
Calculus, Simultaneous Equations & Series Solver
Step-by-step calculus integration by parts, simultaneous linear equations solver, Fourier / Taylor series, and linear programming bounds.
Percentage Change, Increase & Decrease Calculator
Calculate percentage difference, percentage increase/decrease, and relative variation between two numbers.
Ratio & Proportion Solver
Solve proportions A:B = C:D for missing terms, simplify ratios, and scale proportional quantities.
Pythagorean Theorem & Right Triangle Solver
Calculate hypotenuse, missing side lengths (a² + b² = c²), area, perimeter, and internal angles of right triangles.
Time & Hours
Work Time Card & Overtime Paycheck Calculator
Calculate daily employee work hours, timesheet hours, meal break deductions, 1.5x overtime pay, and weekly wage subtotals.
Date to Date Duration & Exact Age Calculator
Calculate exact duration between two dates in years, months, days, hours. Calculate exact birth age or add/subtract days from a target date.
Hourly Wage to Annual Salary Converter
Convert hourly wage to annual salary and annual income to hourly rate. Calculates 40-hr regular pay, 52 weeks, overtime pay, and monthly paycheck.
Business Days & Calendar Date Duration Calculator
Calculate business working days between two dates excluding weekends and holidays. Add or subtract work days from any calendar date.
Exact Chronological Age & Birthday Calculator
Calculate exact age in years, months, days, hours, and countdown total days until your next birthday.
Work Time Card & Paid Hours Calculator
Track daily clock-in/out times, deduct unpaid lunch breaks, and calculate total weekly work hours and gross pay.
Unit & Materials
Universal Unit & Currency Converter
Convert British Pounds (GBP) to USD dollars, kg to pounds, cm to feet & inches, and standard metric/imperial units.
Square Footage & Concrete Volume Yardage Calculator
Calculate room surface area in square feet/meters and concrete volume in cubic yards or 80lb/60lb bags for slabs, footings, and steps.
Mulch, Topsoil, Gravel & Asphalt Yardage Calculator
Calculate material volume in cubic yards, 2 cu ft / 3 cu ft bags, and tons for landscaping mulch, topsoil, gravel, sand, and asphalt paving.
Paint Gallons & Stair Stringer Step Calculator
Calculate paint gallons needed for wall surface area excluding windows/doors, and stair stringer step rise and run measurements for builders.
Electrical & Energy Calculator (Watts, Amps, Volts & kWh)
Calculate Ohm\
Land Area, Square Meter (m²) & Cubic Meter (m³) Calculator
Convert land plot dimensions into square meters (m²), acres, hectares, cubic meters (m³), and estimated material weights.
Speed, Distance & Time Calculator
Solve for speed (mph, km/h), distance, or travel duration with integrated unit conversions.
Screen Aspect Ratio & Resolution Resizer
Calculate aspect ratios (16:9, 4:3, 21:9), scale pixel dimensions, and determine total megapixel count.
Biology
Ovulation & Fertility Window Calculator
Calculate your fertile window, ovulation day, and best conception days based on your cycle length.
Blood Pressure Categories & Mean Arterial Pressure
Classify systolic/diastolic readings into AHA categories (Normal, Elevated, Stage 1/2 Hypertension) and calculate MAP.
Child BMI & Growth Percentile Calculator
Calculate a child's BMI-for-age and weight/height growth percentile using CDC reference data for ages 2–20.
Chemistry
pH & Acid-Base Strength Calculator
Calculate pH from hydrogen ion concentration [H⁺], pOH, and identify strong acids vs bases on the pH scale.
Ideal Gas Law Calculator (PV = nRT)
Solve for any variable in the Ideal Gas Law — pressure, volume, moles, or temperature.
Solution Dilution Calculator (C₁V₁ = C₂V₂)
Calculate final concentration or volume when diluting a stock solution using the C₁V₁ = C₂V₂ equation.
Radioactive Half-Life & Decay Calculator
Calculate remaining quantity of radioactive isotope, half-life period, and decay elapsed time.
Physics
Projectile Motion Calculator
Calculate horizontal range, maximum height, time of flight, and impact velocity of a projectile launched at any angle.
Ohm's Law & Power Calculator
Solve for voltage (V), current (I), resistance (R), and power (P) using Ohm's Law — V = IR and P = IV.
Work, Energy & Power Calculator
Calculate mechanical work done, potential energy, kinetic energy, and power output from force, mass, height, and velocity.
Mass, Density & Volume Calculator (ρ = m/V)
Solve for mass, volume, or density (ρ = m/V) and compare material buoyancy relative to water.
Torque & Rotational Force Calculator
Calculate rotational torque (τ = F × r × sin θ) in Newton-meters (N·m) or foot-pounds (ft-lb).
Sports
Running Pace & Marathon Race Time Calculator
Calculate your running pace per mile/km, finish time for 5K, 10K, half marathon, or full marathon from any two known values.
VO₂ Max & Aerobic Fitness Level Estimator
Estimate your VO₂ Max (maximal oxygen uptake) using the Rockport walk test or heart rate method and assess aerobic fitness.
1RM One Rep Max & Powerlifting Calculator
Estimate your 1 Rep Max (1RM) for squat, bench press, and deadlift using Brzycki, Epley, or Lombardi formulas.
Everyday Life
Sleep Cycle & Bedtime Calculator
Calculate optimal bedtime or wake-up time based on 90-minute sleep cycles so you wake up refreshed.
Road Trip Fuel Cost & MPG Calculator
Estimate total gas cost for any road trip distance based on fuel efficiency (MPG), gas price, and miles driven.
Discount & Sale Price Calculator
Calculate final sale price after percentage discount, markup amount, and total savings on any original price.
Ecology
Personal Carbon Footprint Calculator
Calculate your annual carbon footprint in tonnes CO₂ from home energy, car travel, flights, and diet.
Solar Panel Savings & Payback Period Calculator
Estimate annual electricity savings, 25-year ROI, and payback period for rooftop solar panel installation.
Water Footprint & Daily Usage Calculator
Calculate your daily water consumption in gallons from showers, laundry, dishwasher, and faucet usage.
Tree CO₂ Absorption & Carbon Offset Calculator
Estimate annual CO₂ sequestration per tree species, forest plot size, and 10-year environmental carbon offset.
Food & Cooking
Cooking Measurement Converter (Cups, ml, oz, tbsp)
Convert cooking measurements between cups, milliliters, tablespoons, teaspoons, ounces, and liters instantly.
Calorie Density & Food Energy Calculator
Calculate calorie density (kcal per gram) of any food and compare energy content across macronutrients.
Alcohol Units & Blood Alcohol Content (BAC) Calculator
Calculate alcohol units in drinks, estimated Blood Alcohol Content (BAC), and time to sober up safely.
Baker's Percentage & Flour Ratio Calculator
Calculate baker's percentages, hydration levels, salt ratios, and scale dough batch quantities by flour weight.
Statistics
Z-Score & Percentile Rank Calculator
Calculate z-score from a raw score, mean, and standard deviation. Find the corresponding percentile and probability.
Confidence Interval Calculator (95% & 99%)
Calculate 95% and 99% confidence intervals for sample means using z or t distributions and standard error.
Sample Size Calculator for Surveys & A/B Tests
Determine the minimum statistically valid sample size for surveys, polls, or A/B tests at any confidence level.
Standard Deviation, Variance & Mean Calculator
Calculate sample and population standard deviation, variance, mean, median, min, max, and sum of squares.