Calculators & Converters

Free calculators: margin, mortgage, compound interest, freelance tax, crypto ROI, BMI, TDEE, calorie, macro, unit, and currency converter.

• IPv4 Subnet Calculator — Compute network and broadcast addresses, host range, usable hosts, subnet mask, wildcard, and CIDR for any IPv4 address and prefix.
• Calculator — A fast online calculator with Simple and Expert (scientific) modes and a running history — like the calculator on your phone, right in your browser.
• Scientific Calculator — A full scientific calculator — trig, logs, powers, roots, factorial, constants, and memory — with keyboard support.
• Percentage Calculator — Find a percentage of a number, increase or decrease by a percent, what-percent-of, and reverse percentages.
• Unit Converter — Convert length, weight, data storage, temperature, volume, speed, area, and time.
• Currency Converter — Real-time fiat and crypto currency conversion with live exchange rates.
• Mortgage Calculator — Compute monthly payments, total interest, and an amortization preview for any loan.
• Loan Calculator — Compute the monthly payment, total interest, and payoff time for any loan, with a full amortization preview.
• Auto Loan Calculator — Estimate a car payment including down payment, trade-in, sales tax, and fees — see the amount financed and total cost.
• Amortization Calculator — See a full payment-by-payment amortization schedule, and how much interest and time an extra monthly payment saves.
• Payment Calculator — Solve for the monthly payment from a loan term, or the payoff time from a fixed monthly payment.
• Simple Interest Calculator — Calculate simple interest and ending balance from a principal, rate, and time — with a compound-interest comparison.
• Interest Rate Calculator — Back-solve the annual interest rate of a loan from its amount, monthly payment, and term.
• Compound Interest — Project investment growth with recurring contributions across any compounding frequency.
• Investment Calculator — Project an investment’s end balance from a starting amount, return rate, time, and recurring contributions.
• Finance Calculator (TVM) — A time-value-of-money solver — compute future value, present value, payment, periods, or rate from the others.
• Retirement Calculator — Project your retirement nest egg from current savings, monthly contributions, and expected return — and what income it supports.
• Inflation Calculator — See how prices change over time using historical U.S. CPI between two years, or a fixed average inflation rate.
• Crypto ROI Calculator — Calculate profit, ROI %, breakeven price, and annualized return for any crypto trade.
• Creator Earnings Calculator — Estimate YouTube, TikTok, and Instagram creator earnings from views (RPM) or follower count and sponsored posts, with typical 2026 ranges per platform.
• Aspect Ratio Calculator — Solve width or height for any aspect ratio — 16:9, 9:16, 4:5, 1:1, and custom — and get the simplified ratio. Lock one dimension and the other follows.
• Engagement Rate Calculator — Calculate your social media engagement rate from likes, comments, saves, and shares against followers or reach — with industry benchmark bands.
• Margin Calculator — Calculate gross profit, markups, and margins for retail or service pricing.
• Income Tax Calculator — Estimate U.S. federal income tax, effective and marginal rates, and take-home pay by filing status (2024 brackets).
• Salary Calculator — Convert pay between hourly, daily, weekly, bi-weekly, monthly, and annual using your hours and weeks worked.
• Sales Tax Calculator — Add or remove sales tax — solve the net, tax, or gross amount from any two, at any tax rate.
• Freelance Tax Estimator — Estimate self-employment and income tax owed on freelance revenue after deductions.
• BMI Calculator — Compute body mass index from height and weight with WHO category breakdown.
• BMR Calculator — Calculate your basal metabolic rate (Mifflin-St Jeor and Harris-Benedict) and daily calories at each activity level.
• Daily Calorie Needs — Target daily calories for losing, maintaining, or gaining weight based on TDEE and goal.
• TDEE Calculator — Estimate basal metabolic rate (BMR) and total daily energy expenditure using Mifflin-St Jeor.
• Macro Tracker — Split daily calories into protein, carbs, and fat grams for any diet preset.
• Body Fat Calculator — Estimate body fat percentage with the U.S. Navy method, plus fat mass, lean mass, and your fitness category.
• Ideal Weight Calculator — Find your ideal body weight by the Robinson, Miller, Devine, and Hamwi formulas, plus your healthy BMI range.
• Pace Calculator — Solve running pace, time, or distance — with speed and predicted finish times for 5K, 10K, half, and full marathon.
• Pregnancy Calculator — Track gestational age, trimester, due date, and milestones from your LMP, due date, or conception date.
• Due Date Calculator — Estimate your pregnancy due date from your last menstrual period or conception date, with current progress and milestones.
• Conception Date Calculator — Estimate the conception date and fertile window from a due date or last menstrual period.
• Age Calculator — Find exact age in years, months, and days between two dates, plus totals and a next-birthday countdown.
• Date Difference Calculator — Days, weeks, months, and years between two dates — plus a business-day mode that skips weekends and your holidays.
• Date Calculator — Add or subtract years, months, weeks, and days from a date to find the resulting date and day of week.
• Time Calculator — Add or subtract durations in days, hours, minutes, and seconds — and convert a duration between time units.
• Hours Calculator — Add up worked hours from start and end times with breaks — a quick timesheet with decimal hours and optional pay.
• Epoch Converter — Transform Unix timestamps to human-readable dates and local timezones.
• GPA Calculator — Calculate your weighted GPA from course letter grades and credit hours on a 4.0 scale.
• Grade Calculator — Compute your weighted course grade from assignment scores, or the score you need on the final to hit a target.
• Fraction Calculator — Add, subtract, multiply, and divide fractions with exact, simplified results — plus decimal-to-fraction conversion.
• Triangle Calculator — Solve a triangle from any 3 known sides/angles (SSS, SAS, ASA, AAS, SSA) — all sides, angles, area, and type.
• Standard Deviation Calculator — Compute mean, median, variance, and population/sample standard deviation from a list of numbers.
• Random Number Generator — Generate cryptographically strong random integers or decimals in a range, with unique and sorted options.
• Concrete Calculator — Estimate concrete volume for slabs, footings, and round columns in cubic yards or meters, plus the number of bags.