Calculator Suite
Free online calculators for math, finance, engineering, health, and more — fast and accurate.
📐 Math Calculators
- Percentage CalculatorSolve all percentage problems
- Fraction CalculatorAdd, subtract, multiply, divide fractions
- Quadratic FormulaSolve ax² + bx + c = 0 with real or complex roots
- GCF & LCM CalculatorGreatest common factor and least common multiple
- Scientific NotationConvert between decimal and scientific notation
- Right TriangleSolve sides, angles, area via Pythagorean theorem
- Standard DeviationMean, median, mode, range, variance, and std dev
- Percent ErrorCompare experimental to theoretical value
- Percentage DifferencePercent difference between two values
- Tip CalculatorGratuity & bill split between any number of people
- Discount CalculatorSale price, discount %, or list price
- Sales Tax CalculatorAdd or extract sales tax from a price
- Vote PercentageElection & poll vote share with winner
- Descriptive StatisticsFull stats: skewness, kurtosis, quartiles, CV
- Quartile & IQRQ1, Q2, Q3, IQR with outlier detection
- Percentile CalculatorNth percentile + every-5th-percentile table
- Z-Score CalculatorThree methods: raw value, sample, two-sample
- Combinations & PermutationsnCr, nPr — with or without replacement
- Factorial Calculatorn!, n!!, n!!! — arbitrary precision
- Pascal's TriangleGenerate any number of rows
- Fibonacci CalculatorNth term, sequence & golden ratio
- Permutation VariantsEven, odd, and circular permutations
🧮 Algebra & Calculus (Step-by-Step)
- Equation SolverLinear, quadratic, cubic, rational & trig equations — with steps
- System of Equations2 or 3 equations by elimination, exact fractions
- Factor, Expand & SimplifyFactor polynomials, expand brackets, reduce fractions
- Derivative CalculatorStep-by-step rules, 2nd/3rd derivatives, tangent line, graph
📏 Geometry Calculators
- Circle & AnnulusArea, radius, circumference, diameter, ring area
- Rectangle & SquareArea, perimeter, and diagonal
- Parallelogram & RhombusArea, perimeter, height, diagonals
- Regular PolygonArea, perimeter, apothem, angles (3–14 sides)
- Pythagorean TheoremSolve for hypotenuse or either leg
- Triangle SolverSSS, SAS, ASA, AAS — full solution
- CubeSurface area, volume, diagonals
- Rectangular PrismVolume, surface area, space diagonal
- Sphere & HemisphereSurface area, volume, circumference
- CylinderBase, lateral, total area + volume
- ConeSlant height, surface area, volume
🔁 Engineering · Unit Conversion
- Length Convertermm, cm, m, km, in, ft, yd, mi
- Area Converterm², ft², acres, hectares
- Volume ConverterL, m³, gallons, ft³, yd³
- Mass & Weight Converterg, kg, tonne, oz, lb, tons
- Pressure Converterpsi, bar, kPa, MPa, inH₂O
- Temperature Converter°C, °F, K, °R
- Torque ConverterN·m, lb·ft, lb·in, kgf·m
- Force ConverterN, kN, lbf, kip, kgf
- Flow Rate ConverterL/s, m³/h, GPM, CFM
- Power ConverterW, kW, hp, BTU/h, tons
- Energy ConverterJ, kWh, BTU, kcal, therm
- Speed Converterm/s, km/h, mph, ft/s, knots
- Density Converterkg/m³, g/cm³, lb/ft³
⚡ Engineering · Electrical
- Ohm's Law CalculatorEnter any 2 of V, I, R, P
- Voltage Drop CalculatorCopper/aluminium, 1-phase, 3-phase, DC
- Wire Size CalculatorSmallest AWG for ampacity and voltage drop
- AWG ↔ mm² ConverterWire gauge diameter and area
- Breaker Size CalculatorLoad current × 125% → standard breaker
- Battery Runtime CalculatorBattery / UPS backup time
- Electricity Cost CalculatorAppliance cost per day, month, year
- Solar Panel Size CalculatorArray kW and panel count
- Resistor Color Code4-band and 5-band decoder
- Series & Parallel ResistorsEquivalent resistance
🏗️ Engineering · Construction & Civil
- Concrete CalculatorSlabs, footings, columns + bags
- Rebar Weight Calculatord²/162 kg per meter
- Brick & Block CalculatorBricks and mortar for a wall
- Paint CalculatorLiters / gallons for a room
- Tile CalculatorTiles, boxes and waste
- Flooring CalculatorLaminate, vinyl, hardwood boxes
- Drywall CalculatorSheets, screws, compound
- Roof Pitch Calculatorx/12 pitch ↔ angle ↔ %
- Stair CalculatorRisers, treads, stringer, code check
- Gravel, Mulch & Soil CalculatorCubic yards, tons, bags
- Slope & Grade CalculatorGrade %, angle, ratio, ADA check
⚙️ Engineering · Mechanical & Fluids
- Pipe Flow Velocity CalculatorQ = A·v, size a pipe
- Pipe Pressure Drop (Hazen-Williams)Friction loss in water pipes
- Tank Volume CalculatorVertical, horizontal, rectangular, partial fill
- Pump Power CalculatorHydraulic and shaft power
- Gear Ratio CalculatorRatio, output RPM and torque
- Belt & Pulley CalculatorDriven RPM, belt speed, belt length
- Torque, Power & RPM CalculatorP = T·ω — enter any 2
- Bolt Torque CalculatorT = K·D·F
- Thermal Expansion CalculatorΔL = α·L·ΔT
🌡️ Engineering · HVAC & Energy
- AC BTU CalculatorRoom air-conditioner size
- Heat Loss CalculatorQ = U·A·ΔT
- CFM ↔ Air Changes per HourVentilation rate for a room
- Fuel Economy & Trip CostL/100km ↔ MPG + trip cost
🏛️ Engineering · Structural
- Beam Deflection CalculatorSimply supported: moment, shear, deflection
- Stress & Strain Calculatorσ = F/A, ε = ΔL/L, E = σ/ε
- Section Properties CalculatorArea, I, S, r for common shapes
- Factor of Safety CalculatorFoS, margin, utilization
🎓 School Calculators
- GPA CalculatorGrade point average on the 4.0 scale
- Final Exam GradeScore needed on the final to hit your target
- Weighted GradeCourse grade from weighted assignments
💰 Finance Calculators
- Mortgage CalculatorPITI breakdown with tax & insurance
- Amortization CalculatorFull schedule + extra payment impact
- Mortgage Payoff CalculatorSave time & interest with extra payments
- FHA Loan CalculatorPayment with FHA mortgage insurance (MIP)
- VA Mortgage CalculatorVA loan with funding fee estimation
- Home Equity LoanBorrow against your home equity
- HELOC CalculatorDraw & repayment phase payments
- Auto Loan CalculatorCar payment with tax, trade-in & fees
- Auto Lease CalculatorLease payment from cap cost & money factor
- Interest CalculatorSimple or compound interest with growth table
- Compound InterestGrow savings with compound interest
- Interest Rate CalculatorFind implied simple or compound rate (CAGR)
- Simple Interest CalculatorI = P × r × t with daily & monthly breakdown
- CD CalculatorCertificate of Deposit balance & APY
- Bond CalculatorBond price from coupon rate & market yield
- Loan CalculatorMonthly payment & amortization table
- EMI CalculatorEquated Monthly Installment for any loan
- Affordability CalculatorMax loan, car, or house from your monthly payment
- Interest-Only MortgageIO phase + amortizing phase payments
- Property Tax CalculatorAnnual & monthly tax (% or mill rate)
- Loan Comparison TablePayment matrix across rates and terms
- Equal Principal AmortizationSchedule with fixed principal each month
- APR CalculatorTrue APR including loan fees & origination
- Effective Annual Rate (EAR)Nominal → effective at any compounding
- Nominal Rate CalculatorEffective → nominal stated rate
- Rate ConversionAnnual → periodic; equivalent across frequencies
- Present Value (PV)Lump sum, annuity, growing annuity + PVIF/PVIFA
- Future Value (FV)Lump sum, annuity, growing annuity + FVIF/FVIFA
- PV of Cash FlowsDiscount even or uneven cash flows
- FV of Cash FlowsCompound cash flows forward to a future date
- Net Present Value (NPV)Investment evaluation with decision rule
❤️ Health Calculators
- BMI CalculatorBody Mass Index for adults
- Carb CounterCarbs, fiber & net carbs in rice, bread, tortillas…
- Protein CalculatorDaily need + protein in chicken, salmon, beef…
- Fat CalculatorDaily fat & saturated fat, fat in foods
- Nutrition FactsCarbs, protein & fat in 94 popular foods
- Period CalculatorPredict next periods, ovulation & fertile window
- Pregnancy CalculatorDue date, conception, current week & trimesters
- Animal GestationDue dates for 17 species — dogs, cats, cattle…
- Pace CalculatorRunning pace, finish time, race splits
- Target Heart RateMax HR & training zones (Tanaka/Fox/Karvonen)
📅 Date & Time
- World ClockLive time in New York & 140+ cities worldwide
- Cost of Living vs New YorkCompare 40+ US cities and 90+ countries; equivalent salary
- Date CalculatorDays between dates & date math