Multi-category unit converter, loan amortization, percentages, BMI, GPA, and math calculators.
Convert between metric and imperial measurements.
Convert across 10+ categories: Length, Weight, Temperature, Area, Volume, Speed, Energy, Pressure, Power, and Data Storage.
Convert between metric and imperial length units (mm, cm, m, km, in, ft, yd, mi).
Convert between metric and imperial weight units (mg, g, kg, oz, lb, metric ton, US ton).
Convert between Celsius, Fahrenheit, Kelvin, and Rankine temperature scales.
Convert between Liters, Milliliters, Gallons, Quarts, Pints, Cups, and Fluid Ounces.
Convert between square meters, square feet, square yards, acres, hectares, and square miles.
Convert between km/h, mph, m/s, knots, and feet per second.
Convert between Pascal (Pa), Bar, PSI, Standard Atmosphere (atm), and Torr.
Convert between Joules, Kilojoules, Calories, Kilocalories (kcal), kWh, and BTU.
Convert between Watts (W), Kilowatts (kW), Megawatts (MW), Horsepower (hp), and BTU/h.
Convert between Bytes, Kilobytes (KB), Megabytes (MB), Gigabytes (GB), Terabytes (TB), and Bits.
Work out repayments, growth, and returns over time.
Calculate monthly loan payments, total interest paid, and full payoff summary.
Calculate monthly mortgage payments including principal, interest, property tax, and insurance.
Calculate a home down payment amount and remaining loan amount from the purchase price and down payment percentage.
Calculate investment compound growth over time with annual/monthly compounding.
Calculate the future value, total investment, and estimated returns of a monthly SIP (Systematic Investment Plan).
Calculate net profit, percentage ROI, and annualized rate of return on investments.
Calculate how inflation affects purchasing power — what an amount will be worth in the future, or was worth in the past.
Calculate gross and net rental yield from a property's price, annual rent, and annual expenses.
Quick sums for shopping, bills, and trips.
Calculate X% of Y, percentage increase/decrease, percentage difference, and ratio.
Calculate final sale price and total money saved with single or stacked discounts.
Calculate tip amount, total bill with gratuity, and split cost per person.
Add or remove GST from an amount instantly, with CGST/SGST split.
Estimate trip fuel cost from distance, fuel efficiency, and fuel price, including cost per kilometer.
Calculate the cost of charging an electric vehicle from battery capacity, charge range, electricity rate, and charger efficiency.
Set prices and find the point where you break even.
Calculate gross profit, net margin percentage, and markup from cost and revenue.
Convert between markup percentage and profit margin percentage.
Calculate profit margin and markup for a product sold through a marketplace, accounting for percentage and fixed platform fees.
Calculate the break-even point in units and revenue from fixed costs, variable cost per unit, and price per unit.
Body metrics, date maths, and academic grades.
Calculate BMI from height and weight, with WHO category classification.
Estimate Basal Metabolic Rate (BMR) and daily calorie needs for maintenance or weight goals.
Calculate exact age in years, months, days, hours, and next birthday countdown.
Find the number of days between two dates, or add/subtract days, weeks, months, or years from a date.
Calculate cumulative college/high school GPA on a 4.0 weighted scale.
Calculate overall class grade and the required score on final exam to get target grade.
Estimate quantities for a job, including wastage.
Calculate concrete volume and the cement, sand, and aggregate quantities needed from slab dimensions and a mix ratio.
Calculate how many tiles and boxes you need from room dimensions, tile size, and wastage allowance.
Calculate how many bricks you need for a wall from its dimensions, brick size, and mortar joint thickness.
Calculate how many liters of paint you need from wall area, doors/windows to exclude, coverage rate, and number of coats.
Calculate the weight of steel reinforcement bars (rebar) from diameter, length, and quantity.
Convert between carpet area, built-up area, and super built-up area using standard real-estate loading factors.
Size cables, inverters, batteries, and panel arrays.
Solve for voltage, current, resistance, or power given any two known values, using Ohm's Law and the power equation.
Get a recommended copper wire gauge (AWG) for a given load current, based on standard ampacity ratings and derating.
Calculate voltage drop and drop percentage over a cable run from current, length, conductor resistance, and system voltage.
Calculate the solar system size and number of panels needed from your daily energy usage and peak sun hours.
Calculate the battery capacity needed for solar backup power from daily usage, days of autonomy, and depth of discharge.
Calculate the recommended inverter rating (VA) from your total connected load, a safety margin, and power factor.
Estimate solar payback period and lifetime savings from system cost, your electricity bill, expected bill offset, and incentives.
Dimensions, bitrates, and file sizes for audio and video.
Calculate a missing width or height from a known dimension and target ratio (like 16:9), or simplify any W×H into a ratio.
Calculate image DPI (dots per inch) from pixel dimensions and print size, or find the pixel dimensions needed for a target DPI.
Reference standard thumbnail and cover image sizes for YouTube, Instagram, TikTok, and more, and find the closest match for your own dimensions.
Estimate video file size from duration, video bitrate, and audio bitrate.
Calculate audio file size from bitrate and duration, or the bitrate required to hit a target file size.
Convert subtitle files between SRT and WebVTT format, handling timestamp syntax and cue numbering differences.
Convert a tempo in BPM to milliseconds per beat and common note-length timings, useful for delay and reverb settings.
Frame rates, mouse sensitivity, and channel earnings.
Convert between frame rate (FPS) and frame time in milliseconds, useful for understanding game and video performance.
Calculate effective DPI (eDPI) from mouse DPI and in-game sensitivity, or convert your sensitivity to a new DPI while keeping the same feel.
Build Minecraft's §-prefixed color and formatting codes for chat, signs, and command text.
Estimate monthly YouTube ad revenue from views, RPM, and the percentage of monetized views.
Chemistry values and number notation.
Calculate pH and pOH from hydrogen or hydroxide ion concentration, with acidic/basic/neutral classification.
Solve for molarity, moles, or volume in the M = mol/L equation, with optional mass-to-moles conversion via molar mass.
Count the significant figures in a number and round it to a chosen number of significant figures.
Convert a decimal number to scientific notation, or convert scientific notation back to a plain decimal number.
This collection brings together 65 free online calculators and unit converters covering everyday money questions, health and fitness numbers, academic grading, construction quantities, electrical sizing, solar system design, and media and content planning. The financial tools handle loan and mortgage payments with complete amortization schedules, compound interest and SIP growth projections, ROI, GST and sales tax, break-even points, and profit margins. The unit converters translate between metric and imperial length, weight, volume, area, speed, pressure, energy, power, temperature, and data storage units. Trade and construction calculators estimate tile, brick, paint, concrete, steel, and carpet-area quantities including wastage allowances, while the electrical set covers Ohm’s law, wire sizing, and voltage drop. Every calculator runs entirely in your browser, so the figures you enter — salaries, loan balances, health measurements — are never uploaded to a server or stored anywhere. All of them are free, need no signup, and recalculate instantly as you adjust any input.
Yes. Every calculator and converter in this category is completely free with unlimited use, no signup, no account, and no usage limits.
Yes. All calculations run entirely in your browser using client-side JavaScript. The values you enter are never uploaded to a server, logged, or stored anywhere.
Use the loan calculator for auto, personal, and student loans, and the mortgage calculator when you need to include a down payment, property tax, insurance, and HOA fees. Both produce a full month-by-month amortization schedule you can download as CSV.
Yes. Every converter handles metric and imperial units in both directions, including length, weight, volume, area, speed, pressure, energy, power, temperature, and digital storage.
Financial calculations use arbitrary-precision decimal arithmetic to avoid floating-point rounding errors, and the converters use standard published conversion factors. Results are estimates for planning and should not replace advice from a professional.
Yes. Every calculator is responsive and works in any modern mobile or desktop browser, with numeric keypads on number inputs and no app install required.
Once a calculator page has loaded, the math runs locally in your browser, so it keeps working if your connection drops. You need a connection only to load the page itself.
No. Every result is an estimate for informational and planning purposes only. Consult a qualified lender, accountant, or financial advisor before making financial decisions.
Is BMI Accurate? What the Number Misses
Is BMI accurate? It is reliable for populations and unreliable for individuals. Here is what BMI measures well, where it fails, and what to use alongside it.
What Is a Healthy BMI? The Ranges Explained
A healthy BMI range for adults is 18.5 to 24.9. See the full WHO BMI chart, what each category means, where the cut-offs come from, and how to read yours.
How Many Calories Do You Actually Need?
Daily calorie needs vary far more than the 2,000 kcal label figure suggests. See the general population ranges, what drives them, and how to estimate your own.
BMR vs TDEE: Understanding Your Calorie Baseline
BMR vs TDEE explained: BMR is what you burn at rest, TDEE is BMR times an activity factor. See both formulas, the multipliers, and worked examples.
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