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Free calculators for mortgages, loans, retirement and taxes — and for standard deviation, body mass index, bags of concrete, working days and the score you need on a final. Each one shows its formula, assumptions and sources.
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- Money PlannerNot sure where to start? Enter your income once and see every option compared, in a sensible order.Start here
- Mortgage PaymentMonthly payment, PITI, and total interest for US or Canadian loans.Mortgages & Home
- Home AffordabilityHow much house you can afford from income, debts, and down payment.Mortgages & Home
- RefinanceMonthly savings, break-even point, and lifetime cost of refinancing.Mortgages & Home
- Rent vs. BuyCompare the true cost of renting against buying over your time frame.Mortgages & Home
- Loan PaymentPayment, total interest, and extra-payment savings for any loan.Loans
- Auto LoanCar payment with sales tax, trade-in, and down payment.Loans
- Student LoanPayoff time and interest, with the impact of paying extra.Loans
- Debt Snowball vs. AvalancheCompare payoff strategies across all your debts side by side.Debt Payoff
- Debt-to-Income RatioFront-end and back-end DTI that lenders use to qualify you.Debt Payoff
- Credit Card PayoffPayoff time and interest versus paying only the minimum.Credit Cards
- Balance TransferWhether a 0% promo offer beats staying on your current card.Credit Cards
- Savings GoalThe monthly contribution needed to reach a target by a date.Savings
- Emergency FundYour target cushion and how long it takes to build it.Savings
- CD & GICMaturity value and APY for a certificate of deposit or GIC.Savings
- Retirement SavingsProject a retirement path with transparent assumptions.Retirement
- 401(k) & RRSPWorkplace-plan growth with employer match and raises.Retirement
- Roth vs. TraditionalAfter-tax outcome of Roth versus traditional contributions.Retirement
- FIRE / Early RetirementYour financial-independence number and the age you could reach it.Retirement
- Compound InterestProject growth over time with recurring contributions.Investing
- Investment GrowthFuture value of a lump sum plus regular investing.Investing
- Stock Return & ROITotal and annualized return, including dividends and fees.Investing
- Stock Average CostWeighted average cost across every purchase you make.Investing
- Dividend IncomeAnnual income, growth, and reinvested value from dividends.Investing
- Dollar-Cost AveragingWhere steady, periodic investing could land over time.Investing
- CAGRThe compound annual growth rate between two values.Investing
- Rule of 72How long it takes an investment to double at a given rate.Investing
- Bond Price & YieldHow price, coupon, yield, and maturity interact.Investing
- Futures P&L & MarginEducational tick-based profit, loss, and margin math.Investing
- InflationFuture cost and the eroding purchasing power of money.Investing
- Sales TaxTax amount and total for any price and rate.Taxes
- Capital Gains TaxGain, tax owed, and net profit on an investment sale.Taxes
- 50/30/20 BudgetSplit take-home pay across needs, wants, and savings.Budgeting & Net Worth
- Net WorthTotal assets minus liabilities for a clear snapshot.Budgeting & Net Worth
- Simple InterestInterest and total on a principal without compounding.Investing
- Present ValueWhat a future sum is worth in today's dollars.Investing
- Future ValueWhat a lump sum grows to at a given rate.Investing
- Millionaire (Time to $1M)How long until your savings reach a target like $1M.Savings
- Coast FIREWhether today's savings alone can carry you to retirement.Retirement
- Paycheck (Take-Home)Estimate net pay after pre-tax deductions and tax.Income & Pay
- Hourly to SalaryTurn an hourly wage into annual, monthly, and weekly pay.Income & Pay
- Salary to HourlyConvert an annual salary into an hourly rate.Income & Pay
- Overtime PayRegular plus time-and-a-half (or custom) overtime pay.Income & Pay
- Profit MarginGross margin, markup, and profit from cost and revenue.Business & Sales
- MarkupSelling price and profit from cost and a markup rate.Business & Sales
- Break-EvenUnits and revenue needed to cover your fixed costs.Business & Sales
- ROIReturn on investment and net profit from any outlay.Business & Sales
- PercentagePercent of a number and percentage change between two.Everyday Math
- TipTip amount, total, and the split per person.Everyday Math
- Discount & Sale PriceSale price and savings from a percent-off deal.Everyday Math
- Price Per UnitUnit price so you can compare package sizes.Everyday Math
- Mortgage PayoffHow much extra monthly payments cut your years and interest.Mortgages & Home
- Biweekly MortgageBiweekly vs. monthly payments—interest and time saved.Mortgages & Home
- 15- vs 30-Year MortgageCompare a shorter and longer term side by side.Mortgages & Home
- PMIMonthly private mortgage insurance and when it drops off.Mortgages & Home
- Down PaymentDown payment amount and resulting loan from a percentage.Mortgages & Home
- Auto LeaseMonthly lease payment from price, residual, and money factor.Loans
- Loan ComparisonPut two loan offers head to head on payment and total cost.Loans
- Minimum PaymentHow long minimum-only payments really take, and the interest.Credit Cards
- Cash BackYearly cash back across your spending categories.Credit Cards
- College SavingsMonthly saving needed to hit a 529 or RESP goal.Savings
- Annuity PayoutIncome a lump sum can pay out over a set number of years.Retirement
- Safe WithdrawalAnnual and monthly income from the 4%-rule withdrawal rate.Retirement
- Crypto ProfitProfit and return on a buy/sell, net of fees.Investing
- Options ProfitProfit, break-even, and intrinsic value for a call or put.Investing
- Self-Employment TaxUS Social Security and Medicare tax on self-employment income.Taxes
- Net Worth PercentileSee what percentile your net worth is in for your age, US data.Compare Yourself
- Income PercentileRank your income against others in your age group, US data.Compare Yourself
- Savings Rate PercentileSee how your savings rate compares with other US savers.Compare Yourself
- Position SizeRisk a fixed percent per trade and get the exact share count.Trading & Risk
- Risk / RewardR multiple, breakeven win rate, and expectancy for a setup.Trading & Risk
- Short SellingShort-sale profit, borrow fees, and your margin-call price.Trading & Risk
- Margin TradingLeverage, margin interest, and the price that triggers a call.Trading & Risk
- Portfolio HedgeBeta-weighted contracts to hedge a portfolio with index puts or futures.Trading & Risk
- Pivot PointsClassic floor-trader support and resistance from H, L, C.Trading & Risk
- Fibonacci RetracementRetracement and extension prices for any swing high and low.Trading & Risk
- Drawdown RecoveryThe gain needed to climb back from any loss — the cruel math.Trading & Risk
- Kelly CriterionThe growth-optimal bet size from win rate and win/loss ratio.Trading & Risk
- ETF ComparisonTwo funds head to head — expense ratios, returns, and 30-year gap.Investing
- Expense Ratio ImpactWhat a fund's fee quietly costs you over the years.Investing
- Retirement Savings by AgeCompare your 401(k) and IRA balances with US families your age.Compare Yourself
- Debt by AgeSee how your total debt compares with US families your age.Compare Yourself
- Home Equity PercentileCompare the equity in your home with US homeowners generally.Compare Yourself
- Spending by CategoryCompare your housing, food and transport spending with US averages.Compare Yourself
- Budget Rule CheckMeasure what you actually spend against your budget targets.Budgeting & Net Worth
- Savings RateWhat share of income you save, and the years to independence.Budgeting & Net Worth
- Net Worth ProjectionProject net worth forward from contributions and a return.Budgeting & Net Worth
- Cost of Living ComparisonWhat salary a move needs, from cost figures you supply.Budgeting & Net Worth
- True Monthly ExpensesAnnual and quarterly bills spread into a real monthly figure.Budgeting & Net Worth
- True Cost of a PurchaseCost per use, plus the investment growth those dollars give up.Budgeting & Net Worth
- Subscription CostWhat a monthly charge costs over ten years, and per use.Budgeting & Net Worth
- Debt ConsolidationWhether one loan beats your current debts, after the fee and the term.Debt Payoff
- Minimum Payment TrapWhat paying only the minimum costs in years and in interest.Debt Payoff
- Debt-Free DateThe monthly payment that clears every balance by the date you pick.Debt Payoff
- Extra Payment ImpactMonths and interest saved by paying extra on any loan or balance.Debt Payoff
- Pay Off Debt or InvestThe same dollars down both paths, and the return where they tie.Debt Payoff
- Federal Income TaxUS federal tax by bracket, with your marginal and effective rates.Taxes
- Take-Home PaySalary to paycheck after federal tax, FICA and pre-tax deductions.Taxes
- Tax BracketWhich bracket your income lands in, and how much sits in each.Taxes
- Effective Tax RateTotal tax over total income — the rate you actually pay.Taxes
- Quarterly Estimated TaxWhat to send the IRS each quarter on self-employment income.Taxes
- FractionAdd, subtract, multiply, and divide fractions in lowest terms.Math & Statistics
- Decimal to FractionExact fraction for any decimal, including repeating ones.Math & Statistics
- Mean, Median, Mode & RangeEvery centre and spread statistic for a list of numbers.Math & Statistics
- Standard DeviationSample and population deviation, variance, and standard error.Math & Statistics
- Z-ScoreHow many deviations from the mean, and the probability that implies.Math & Statistics
- Confidence IntervalThe margin of error around a sample mean at any confidence level.Math & Statistics
- Sample SizeHow many responses a survey needs for a given margin of error.Math & Statistics
- ProbabilityUnion, intersection, complement, and conditional probability.Math & Statistics
- Permutations & CombinationsnPr and nCr, with exact answers well past the float limit.Math & Statistics
- Factorialn! exactly, however many digits that turns out to be.Math & Statistics
- Quadratic FormulaRoots, discriminant, and vertex for any quadratic equation.Math & Statistics
- Slope & Line EquationSlope, intercept, distance, and midpoint from two points.Math & Statistics
- ExponentPowers with negative and fractional exponents handled properly.Math & Statistics
- Square RootSquare, cube, and nth roots, plus simplified radical form.Math & Statistics
- LogarithmSolve for any of the three parts of log base b of x.Math & Statistics
- RatioSimplify a ratio, solve A∶B = C∶D, or scale one to a total.Math & Statistics
- GCF & LCMGreatest common factor and least common multiple for any list.Math & Statistics
- Prime FactorizationBreak a number into its prime factors, in exponent form.Math & Statistics
- Significant FiguresCount the significant figures in a number, or round to a count.Math & Statistics
- Scientific NotationConvert to and from scientific notation without losing precision.Math & Statistics
- Percent ErrorHow far an observed value sits from the expected one.Math & Statistics
- Area of a ShapeArea for seven shapes, from rectangles to sectors.Math & Statistics
- Volume of a SolidVolume for cubes, cylinders, spheres, cones, and pyramids.Math & Statistics
- Triangle SolverSolve any triangle from SSS, SAS, ASA, or two right-angle sides.Math & Statistics
- CircleRadius, diameter, circumference, and area from any one of them.Math & Statistics
- LengthMetres, feet, inches, miles, and nine more length units.Unit Conversion
- Weight & MassKilograms, pounds, stones, ounces, and tonnes.Unit Conversion
- TemperatureCelsius, Fahrenheit, and Kelvin — an offset, not just a factor.Unit Conversion
- VolumeLitres, gallons, cups, and the US-versus-imperial gap.Unit Conversion
- AreaSquare metres, square feet, acres, and hectares.Unit Conversion
- SpeedMiles per hour, kilometres per hour, knots, and metres per second.Unit Conversion
- Time UnitsSeconds through years, with exact rather than rounded months.Unit Conversion
- Data StorageBytes to terabytes, decimal (GB) and binary (GiB) both.Unit Conversion
- PressurePascals, bar, psi, atmospheres, and millimetres of mercury.Unit Conversion
- EnergyJoules, calories, kilowatt-hours, and British thermal units.Unit Conversion
- AngleDegrees, radians, gradians, and degrees-minutes-seconds.Unit Conversion
- Fuel EconomyUS mpg, imperial mpg, and litres per 100 km — a reciprocal, not a factor.Unit Conversion
- Number BaseBinary, octal, decimal, hex, and every base from 2 to 36.Unit Conversion
- Roman NumeralsArabic to Roman and back, with the subtractive rules applied.Unit Conversion
- Cooking MeasurementsCups, grams, and millilitres — by ingredient, because density differs.Unit Conversion
- BMIBody mass index in metric or imperial, with the WHO bands.Health & Fitness
- BMRResting energy burn by Mifflin-St Jeor, Harris-Benedict, or Katch-McArdle.Health & Fitness
- TDEETotal daily energy expenditure — maintenance calories, three ways.Health & Fitness
- Calorie TargetCalories for a goal weight, and the date you would reach it.Health & Fitness
- MacrosProtein, carbs, and fat in grams from a calorie target.Health & Fitness
- Body FatUS Navy circumference method, with the BMI method alongside.Health & Fitness
- Ideal WeightFour classic formulas plus the healthy-BMI range they disagree with.Health & Fitness
- Lean Body MassEverything that is not fat, by Boer, James, or Hume.Health & Fitness
- Protein IntakeGrams of protein a day for maintenance, loss, or muscle gain.Health & Fitness
- Pregnancy Due DateDue date from last period, conception, or IVF transfer.Health & Fitness
- Running PacePace, time, or distance — fill any two and get the third.Health & Fitness
- One-Rep MaxEstimated 1RM by Epley, Brzycki, and Lombardi, plus a percentage table.Health & Fitness
- Calories BurnedEnergy cost of an activity from its MET value and your weight.Health & Fitness
- Heart Rate ZonesFive training zones by percentage of max or heart-rate reserve.Health & Fitness
- Steps to MilesDistance from a step count, using stride length from your height.Health & Fitness
- Square FootageTotal floor area across several rooms, and the cost per square foot.Home & Construction
- ConcreteCubic yards and bag counts for slabs, footings, columns, and tubes.Home & Construction
- PaintGallons needed once doors, windows, and second coats are counted.Home & Construction
- MulchCubic yards and bags of mulch for a bed at a given depth.Home & Construction
- Gravel & AggregateVolume and tonnage for gravel, sand, or crushed stone.Home & Construction
- TileTile count and boxes, with a waste allowance for cuts.Home & Construction
- FlooringBoxes of laminate, vinyl, or hardwood for a room.Home & Construction
- RoofingSquares and bundles of shingles, adjusted for roof pitch.Home & Construction
- DrywallSheets, joint compound, tape, and screws for a room.Home & Construction
- FencePosts, rails, and pickets from a run length and post spacing.Home & Construction
- StairsRiser count and height, tread depth, and total stringer run.Home & Construction
- BTU & Room SizeHeating and cooling capacity a room needs, by area and climate.Home & Construction
- AgeExact age in years, months, and days on any given date.Time & Date
- Date DurationDays, weeks, and months between two dates.Time & Date
- Add or Subtract TimeThe date a number of days, weeks, or months from another.Time & Date
- Business DaysWorking days between dates, minus US federal holidays.Time & Date
- Time CardWeekly hours from clock-in and clock-out times, breaks deducted.Time & Date
- Time DurationAdd and subtract hours, minutes, and seconds.Time & Date
- Days UntilCountdown from today to any future date.Time & Date
- Day of the WeekWhich weekday any date in history falls on.Time & Date
- Week NumberISO 8601 week number for a date, and the dates in a week.Time & Date
- Military Time24-hour and 12-hour clock, converted both directions.Time & Date
- Unix TimestampEpoch seconds to a UTC date, and back.Time & Date
- Sleep & BedtimeBedtimes and wake times that land between 90-minute cycles.Time & Date
- GradeCurrent grade from weighted assignment categories.Grades & School
- Final GradeThe score you need on the final to hit a target grade.Grades & School
- GPATerm GPA from credits and letter grades, weighted or not.Grades & School
- Cumulative GPANew cumulative GPA after adding a term to your record.Grades & School
- Test GradePercentage and letter grade from questions right and wrong.Grades & School
- Easy GraderThe full score-to-percentage table for a test of any length.Grades & School
- Weighted AverageAverage where each value carries its own weight.Grades & School
- Grade CurveFlat, square-root, and linear-scale curves applied to a class.Grades & School
- Word CounterWords, characters, sentences, and paragraphs in a passage.Everyday Utility
- Random NumberNumbers in a range, unique or repeating, from a seed you can share.Everyday Utility
- Aspect RatioResize while keeping proportion, and name the ratio.Everyday Utility
- Fuel CostWhat a trip costs in fuel, and the cost per person.Everyday Utility
- Gas MileageReal-world mpg or L/100 km from a tank and an odometer.Everyday Utility
- Electricity CostWhat an appliance costs to run per day, month, and year.Everyday Utility
- Dog AgeDog years by size class, and by the 2019 epigenetic curve.Everyday Utility
- Cat AgeCat years using the AAFP/AAHA feline life stages.Everyday Utility
- Tire SizeCompare two tire sizes for diameter, and speedometer error.Everyday Utility
- Recipe ScalerScale ingredient quantities to a different number of servings.Everyday Utility
- Reading TimeHow long a piece takes to read or to say out loud.Everyday Utility
- Wind ChillWhat the cold actually feels like, by the NWS 2001 formula.Everyday Utility
- Dimensional WeightBillable shipping weight when a box is big but light.Everyday Utility
200 calculators across 21 categories. Every one shows its formula, assumptions and sources.
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