Everyday calculators, with the math shown
73 calculators for pay, loans, materials, measurements, time, and business math. Every result shows its formula, and units switch between US customary and metric.
How much do I earn per hour?
Per hour
$28.85
Per week
$1,153.85
Per month
$5,000.00
Personal finance
Pay, loans, savings, and debt.
Salary to Hourly CalculatorHourly rate = yearly salary ÷ (hours a week × weeks worked)Hourly to Salary CalculatorYearly salary = hourly rate × hours a week × weeks workedOvertime CalculatorRegular pay = min(hours, threshold) × rateBonus CalculatorBonus = salary × bonus %Gross to Net Pay CalculatorTaxes = gross × (income + payroll + state rates)Sales Tax CalculatorTotal = price × (1 + rate)Loan CalculatorPayment = P × r ÷ (1 − (1 + r)^−n)Mortgage CalculatorLoan = price × (1 − down payment %)Simple Interest CalculatorInterest = principal × rate × yearsCompound Interest CalculatorFV = start × (1 + r)^m + monthly × ((1 + r)^m − 1) ÷ rSavings Goal CalculatorMonthly = (goal − current savings grown) × r ÷ ((1 + r)^m − 1)Debt Payoff CalculatorMonths = −ln(1 − r × balance ÷ payment) ÷ ln(1 + r)Credit Card Interest CalculatorInterest = average daily balance × (APR ÷ 365) × days in cycleRetirement Savings CalculatorProjected = future value of savings and monthly contributionsBudget Calculator (50/30/20)Each bucket = take-home pay × its percentage
Paycheck CalculatorPlannedNeeds maintained federal and state tax tables for the 2026 tax year.
Income Tax EstimatorPlannedNeeds maintained 2026 federal tax brackets and deductions.
Construction
Material estimates in feet or meters.
Concrete CalculatorVolume = length × width × thicknessGravel CalculatorVolume = length × width × depthMulch CalculatorVolume = length × width × depthTopsoil CalculatorVolume = length × width × depthAsphalt CalculatorVolume = length × width × depthExcavation CalculatorVolume = length × width × depthPaint CalculatorWall area = perimeter × heightDrywall CalculatorArea = perimeter × height + ceiling areaFlooring CalculatorArea = length × widthTile CalculatorTile footprint = (tile length + gap) × (tile width + gap)Roofing CalculatorPitch factor = √(1 + (rise ÷ 12)²)Brick CalculatorBricks = wall area × bricks per sq ft × (1 + waste)Fence CalculatorSections = length ÷ post spacing, rounded upDeck CalculatorBoard rows = deck width ÷ (board width + gap)Stair CalculatorRisers = total rise ÷ max riser, rounded upRebar CalculatorBars each way = side ÷ spacing + 1Lumber (Board Feet) CalculatorBoard feet = thickness (in) × width (in) × length (in) ÷ 144
Measurements and conversions
Area, volume, length, weight, and temperature.
Square Footage CalculatorRectangle: length × widthArea CalculatorRectangle: l × wVolume CalculatorBox: l × w × hCubic Feet CalculatorCubic feet = length × width × height (all in feet)Cubic Yard CalculatorCubic yards = length (ft) × width (ft) × depth (ft) ÷ 27Length ConverterResult = value × (size of "from" unit ÷ size of "to" unit)Weight ConverterResult = value × (size of "from" unit ÷ size of "to" unit)Distance ConverterResult = value × (size of "from" unit ÷ size of "to" unit)Temperature Converter°F = °C × 9 ÷ 5 + 32Feet and Inches CalculatorConvert both to inches (feet × 12 + inches), add or subtract, then convert backPercentage CalculatorX% of Y = X ÷ 100 × YRatio CalculatorSimplify: divide both by their greatest common divisor
Time and work
Hours, dates, and pay periods.
Time Card CalculatorDaily hours = clock-out − clock-in − unpaid breakHours CalculatorDuration = end − start − break (adds 24 hours if the end is the next day)Work Hours CalculatorWeekly hours = daily hours × days a weekTime Duration CalculatorConvert to seconds, add or subtract, then convert back to h:mm:ssDate Difference CalculatorDays = end date − start dateBusiness Days CalculatorBusiness days = weekdays from start to end (inclusive) − holidaysVacation Days CalculatorAccrued = yearly days × months worked ÷ 12Weekly Pay CalculatorPay = regular hours × rate + overtime hours × rate × 1.5Monthly Salary CalculatorMonthly = salary ÷ 12; semi-monthly ÷ 24; biweekly ÷ 26; weekly ÷ 52
Business calculators
Margins, pricing, break-even, and growth.
Profit Margin CalculatorProfit = price − costMarkup CalculatorPrice from markup = cost × (1 + markup)Gross Profit CalculatorGross profit = revenue − COGSNet Profit CalculatorNet profit = revenue − COGS − operating expenses − interest − taxesBreak-even CalculatorContribution per unit = price − variable costRevenue CalculatorRevenue = price × unitsOperating Expense CalculatorOperating expenses = sum of overhead categoriesReturn on Investment CalculatorROI = (return − cost) ÷ costCustomer Acquisition Cost CalculatorCAC = marketing and sales spend ÷ new customersCustomer Lifetime Value CalculatorLifetime revenue = order value × orders per year × yearsSales Commission CalculatorCommission = sales up to quota × rate + sales above quota × higher rateDiscount CalculatorSale price = price × (1 − discount 1) × (1 − discount 2)Wholesale Pricing CalculatorWholesale = cost × (1 + wholesale markup)Unit Economics CalculatorContribution = price − product cost − fees − shippingDiscount Impact CalculatorSales needed = (profit per sale now × current sales) ÷ profit per sale at the discountFreelance Rate CalculatorRevenue needed = income goal ÷ (1 − tax rate) + business costsTrue Hourly Earnings CalculatorProfit per piece = price − fees − materials − shippingReturn Cost CalculatorCost per return = fees kept + shipping both ways + item cost × chance of lossCurrency Conversion Fee CalculatorConverted = amount × exchange rateVAT and GST CalculatorGross = net × (1 + rate)
Calculators that show their working
Each calculator lists its formula and a worked example, so you can check the math or redo it on paper. Construction and measurement tools switch between US customary units and metric. Pay and finance tools use the numbers you enter and never guess at tax rules.
Most used: salary to hourly, concrete, profit margin, markup, and mortgage.
About the calculators
Are these calculators free to use?
Yes, all of them, with no sign-up. Your inputs stay in your browser.
Can I use metric units?
Yes. Construction and measurement calculators have a US and metric switch, and they remember your choice.
Why is there no paycheck or income tax calculator yet?
They need tax tables that are kept up to date every year. They are planned, and they will only go live once those tables can be maintained properly.