Fast financial, math, health, date, time, and unit conversion calculators.
Calculate mortgage amortization, monthly loan repayments, compound interest growth, retirement savings, and paycheck taxes.
Calculate BMI body mass index, daily energy expenditure (TDEE), macronutrient splits, body fat, and developmental health metrics.
Solve fractions, percentages, quadratic equations, geometric areas and volumes, and calculate GPA and grades.
Estimate wall paint gallons, ceramic tile counts, flooring square footage, concrete cubic yards, and roofing materials.
Calculate days between dates, chronological age, elapsed work hours, time zone conversions, and road trip fuel costs.
Size off-grid solar arrays and battery banks, calculate AC room BTU cooling requirements, airflow CFM, and pneumatic forces.
Calculate gross profit margins, retail markups, break-even sales volume, return on investment (ROI), and PTO accruals.
Convert length, mass, temperature, area, volume, and fuel economy seamlessly between metric and imperial systems.
Convert American, decimal, and fractional betting odds, calculate payout returns, and model probability distributions.
Calculate percentages, percentage increases, decreases, and percentage differences.
Calculate final sale prices, discount amounts, and savings with sales tax.
Calculate investment growth over time with compound interest and recurring contributions.
Calculate monthly loan payments, total interest paid, and amortization schedules.
Calculate exact days, weeks, months, and years between two calendar dates.
Convert between metric and imperial units for length, mass, volume, temperature, and speed.
Calculate Body Mass Index (BMI) and health category according to WHO standards.
Calculate tip percentages and split the restaurant bill evenly among friends.
Compare working hours and time zones across Accra, London, New York, Tokyo, and global cities.
Calculate monthly mortgage payments, property taxes, homeowners insurance, PMI, and amortization.
Calculate maintenance calories, BMR, and daily calorie targets for weight loss or muscle gain.
Calculate daily grams of protein, carbohydrates, and healthy fats based on your fitness goals.
Calculate estimated delivery date (EDD), gestational age, and key baby milestones.
Estimate body fat percentage, lean body mass, and fat mass using circumference measurements.
Calculate calories burned at complete rest using Mifflin-St Jeor and Harris-Benedict formulas.
Estimate trip gas costs, fuel volume in gallons or liters, and split fares among passengers.
Calculate how much car you can realistically afford based on your income and the 20/4/10 rule.
Calculate required cooling capacity in BTUs and tons based on room dimensions, sunlight, and occupants.
Project future paid vacation hours, pay period earnings, and identify use-it-or-lose-it caps.
Calculate gallons and quarts of paint required for room walls, doors, windows, and ceilings.
Calculate tile count, box requirements, and material square footage with waste buffer.
Calculate total flooring square footage, cartons needed, waste buffer, and trim perimeter.
Calculate concrete volume in cubic yards, cubic meters, and 80lb/60lb pre-mix bag counts.
Calculate roofing squares, bundles of shingles, pitch multipliers, and underlayment rolls.
Calculate block counts, row courses, buried base row, and drainage gravel for retaining walls.
Calculate pool water volume in gallons and liters for rectangular, round, and oval pools.
Calculate fish tank water volume, filled weight, filter flow rate (GPH), and heater wattage.
Calculate solar panels needed, system kW capacity, roof area, and 25-year electric bill savings.
Calculate battery bank capacity in Ah and kWh for off-grid solar, RVs, and backup power.
Calculate continuous and surge inverter wattage for household appliances and off-grid power.
Calculate cubic yards, tons, and bags of gravel, crushed stone, sand, and mulch.
Estimate probable conception dates, ovulation window, and implantation timeline from due date or LMP.
Predict adult target height for boys and girls using the pediatric Tanner mid-parental method.
Calculate estimated Glomerular Filtration Rate (eGFR) using the race-free 2021 CKD-EPI equation and KDIGO staging.
Estimate your cardiovascular heart age and 10-year heart attack risk based on the Framingham model.
Calculate sleep apnea severity (Normal, Mild, Moderate, Severe) from sleep study event counts.
Estimate 10-year and 30-year risk of ASCVD and Heart Failure using the American Heart Association PREVENT equations.
Estimate breast implant volume in cubic centimeters (cc) to reach desired bra cup size.
Estimate 10-year heart attack & stroke risk and heart age under UK NICE NG238 clinical guidelines.
Evaluate NICE threshold guidelines (≥10% 10-yr risk), benefits, side effects, and NNT for statin therapy.
Find your accurate bra band and cup size with UK, US, EU, FR, and AU conversions and sister sizing.
Calculate sales tax, total price, or reverse-calculate pre-tax price with US state & local presets.
Project retirement wealth, employer matching contributions, and 4% safe withdrawal monthly income.
Forecast portfolio growth over 1-40 years with recurring deposits, compounding frequencies, and inflation.
Calculate how extra monthly, annual, or lump-sum payments shorten your mortgage and save interest.
Estimate IRS Form 1040 Line 11 AGI with W-2, 1099, HSA, IRA, and student loan above-the-line deductions.
Solve for periodic payment, maximum affordable loan amount, or loan term with amortization snapshot.
Add or remove Value Added Tax (VAT) and Goods & Services Tax (GST) with international country presets.
Calculate monthly repayments in GBP (£), Loan-to-Value (LTV), and SVR reversion impact.
Compare new remortgage deals against current terms, factor in arrangement fees, and find break-even months.
Calculate fixed monthly loan repayments, total borrowing cost, and compare multi-term loan options.
Calculate interest savings and years saved from overpayments while monitoring UK 10% ERC limits.
Calculate take-home bonus after 22% federal supplemental rate, FICA, and state withholding.
Calculate property flip profit, Maximum Allowable Offer (MAO), and ROI under the 70% rule.
Estimate federal tax liability, progressive brackets, Child Tax Credits, and IRS refund or amount owed.
Free online four-function desktop calculator with memory (M+, M-, MR, MC), percent, square root, and keyboard support.
Full mathematical expression evaluator supporting brackets, powers, scientific notation, and calculation audit log.
Advanced scientific calculator with trigonometry, logarithms, roots, powers, factorials, radian/degree toggle, and physical constants.
Solve right triangle sides (a² + b² = c²), hypotenuse, angles, area, perimeter, and simplified radical expressions.
Calculate semester and cumulative GPA on 4.0 unweighted and 5.0 weighted scales (AP, IB, Honors) with honors projections.
Calculate weighted class grades and determine the exact score needed on your final exam to earn your target letter grade.
Add, subtract, multiply, and divide fractions and mixed numbers with step-by-step LCD, GCD, and simplified answers.
Calculate single event odds, two-event union & intersection (P(A ∪ B), P(A ∩ B)), and permutations & combinations (nPr, nCr).
Calculate area, perimeter, and circumferences for rectangles, circles, triangles, trapezoids, ellipses, and regular polygons.
Calculate volume, surface area, and fluid capacity (liters, gallons) for boxes, cylinders, spheres, cones, pyramids, and capsules.
Evaluate statistical significance, conversion uplift, z-score, p-value, and confidence intervals for split tests.
Solve linear absolute value inequalities (|ax + b| < c, > c) step-by-step with interval notation and graphical number line.
Find global maximum and minimum values of functions on closed intervals [a, b] using the Extreme Value Theorem.
Compute numerical derivatives (f’, f’’), tangent lines, and definite integrals via Simpson’s rule with high precision.
Convert dog age to human years using AVMA breed-size aging curves or UC San Diego’s DNA epigenetic methylation clock.
Predict your puppy’s full-grown adult weight and mature size based on current age, current weight, and breed category.
Calculate elapsed time between timestamps, convert to decimal hours, deduct lunch breaks, and estimate billable earnings.
Calculate exact age in years, months, weeks, days, hours, and minutes, with next birthday countdown and zodiac signs.
Calculate the exact age gap between two people in years, months, and days, and discover the "Twice As Old" milestone.
Estimate your annual greenhouse gas emissions in metric tonnes of CO₂e across home energy, driving, flights, and diet.
Calculate Alcohol By Volume (ABV), ABW, yeast attenuation %, and 12oz calories from Original and Final Gravity.
Calculate statutory and contractual annual leave entitlement for full-time, part-time, pro-rata, and casual 12.07% workers.
Discover your Japanese Feng Shui astrological blueprint: Principal Year Star, Character Month Star, and Expressive Energetic Star.
Add or subtract years, months, weeks, days, and working business days to any date, or count exact days between dates.
Calculate Gross Profit, Gross Margin %, Net Profit Margin %, Operating Income, and Markup percentage instantly.
Determine retail selling prices, gross profit dollars, and equivalent profit margins from your wholesale cost and target markup %.
Determine the exact unit sales volume and revenue required to cover fixed and variable business operating costs.
Compute total ROI %, Annualized Compound Return (CAGR), net profit gain, and inflation-adjusted real returns.
Calculate author earnings, print-on-demand costs, and distributor cuts for Amazon KDP eBooks, paperbacks, and hardcovers.
Calculate local county property or vehicle ad valorem tax based on fair market value, assessment ratios, and millage rates.
Determine the refundable portion of the US Child Tax Credit (Schedule 8812) based on your earned income and tax liability.
Accurate 2024 California state income tax (up to 13.3%), uncapped 1.2% SDI, federal brackets, and net take-home salary.
Calculate monthly dividend income, current yield %, and long-term DRIP compound reinvestment growth for AGNC and high-yield REITs.
Calculate broker sales commission, guaranteed monthly retirement income, and lifetime cash flow returns across annuity contracts.
Calculate board count, exact even spacing, linear footage, and standard 8-ft lumber for vertical slats and board & batten accent walls.
Estimate accessory dwelling unit (granny flat) construction costs, permits, utility hookups, and monthly rental yields.
Calculate tons and cubic yards of ABC stone (crusher run / aggregate base course) with compaction and delivery cost.
Calculate required British Thermal Units (BTU/hr) and electric wattage to heat any room based on dimensions, windows, and insulation.
Calculate CFM airflow, round and rectangular duct air velocity (FPM), and room Air Changes per Hour (ACH).
Calculate true air density (kg/m³), density altitude, and pressure altitude from elevation, temperature, and barometric pressure.
Calculate extension (push) and retraction (pull) force for pneumatic cylinders in pounds force (lbf) and Newtons (N).
Size solar panel arrays, lithium LiFePO4 battery banks (Ah/kWh), and pure sine wave inverters for off-grid cabins and RVs.
Calculate annual, semi-annual, and monthly payments for farmland purchases, tractors, equipment, and livestock financing.
Estimate guaranteed lifelong retirement income, cash refund protections, payout rates, and tax exclusion ratios from an immediate annuity.
Estimate post-augmentation bra cup size, volume in cc, profile projection, and base diameter for silicone and saline implants.
Calculate composite scores and predict 1–5 AP Biology exam grades from Multiple Choice and Free Response (FRQ) raw points.
Predict your AP Euro exam score (1–5) from Multiple Choice, Short Answer (SAQ), DBQ, and Long Essay (LEQ) scores.
Calculate APES composite scores and predict 1–5 exam grades from 80 Multiple Choice questions and 3 FRQ essays.
Learn Japanese Soroban abacus bead representation, mental math (Anzan), and calculate numbers interactively.
Calculate Golden Ratio proportions (φ ≈ 1.618), harmonic design scales, layout splits, and typography hierarchies.
Convert American, Decimal, and Fractional betting odds, calculate implied win probability, profit, and total payout.
Calculate boxing fight moneyline odds, implied victory percentages, and fight bet payouts across weight divisions.
Calculate laps remaining, training hours, XP rates, and Marks of Grace for Old School RuneScape Rooftop Agility courses.
Convert instantly between US MPG, UK Imperial MPG, L/100km, and km/L with trip fuel cost estimation.