High-precision multi-category calculators for finance, engineering, dates, and science
Optimized for high CTR with Google AdSense, Mediavine or Carbon Ads.
Annuity and differentiated monthly installments, interest breakdown, and amortization schedule.
Calculate PITI (Principal, Interest, Taxes, Insurance), PMI, and accelerated payoff savings.
Visualize compound growth with recurring deposits, annual rate, and investment horizons.
Gross to net salary with income tax, social contributions and deductions, monthly and annual.
Tips with bill splitting and sale discounts with final price.
Credit card payoff time, total interest and payoff date.
Live exchange rates with offline fallback for 24 currencies.
Decode 32-bit Float & Int values, swap endianness (ABCD, CDAB, BADC, DCBA), PDU offsets, and CRC-16.
Live ticking Unix epoch, bidirectional date-time translation with milliseconds and timezones.
Calculate usable host range, broadcast address, subnet mask, and wildcard for network admins.
Secure random passwords with entropy meter and strength rating.
Count exact days, business working days, weekends, months, and hours between two dates.
Exact age in years, months, days, weekday of birth, zodiac, and next birthday countdown.
Live countdown to any date with days, hours, minutes and seconds.
Metric and US Customary units with WHO category classifications and target healthy weight.
Bedtimes and wake-up times based on 90-minute sleep cycles.
Calculate percentages, relative ratios, percentage increases/decreases, and discounts.
Convert length, mass/weight, temperature, speed, and area across metric and imperial systems.
Expression calculator with trig, logs, powers and DEG/RAD modes.
Z-score to p-value with one/two-tailed test and significance check.
Room floor area in square feet and square meters.
Square roots and n-th roots of any number.
Z-score and percentile from value, mean and deviation.
Compare two deals by price per unit.
Nest egg from savings, deposits and return.
Due date and current week from last period.
Voltage, current, resistance and power.
pH, pOH and acidity from H+ concentration.
Margin vs markup from cost and price.
Next period and fertile window from cycle.
Test patterns with live matches.
Remaining caffeine by 5-hour half-life.
WPM and accuracy from retyping.
Header and payload of a JSON Web Token.
Annual, monthly and weekly pay.
Billable rate from salary and expenses.
Sun times for any place and date.
Monthly auto loan payment.
Pizzas for your party.
Months to save a target with interest.
Total cost from guests and fixed costs.
Rental yield from price and rent.
Chance the sum reaches target.
Profit and ROI of a flip.
QR codes with PNG download.
Add or extract Value Added Tax (VAT) with international country presets.
Analyze profitability and percentage return on business capital and investments.
Buy or rent? Break-even year with equity, appreciation and rising rent.
Future buying power of money at yearly inflation.
New average price after buying more shares.
Monthly lease payment from price, residual, APR and term.
Monthly deposit to reach your target with compound interest.
Split income into needs, wants and savings.
New payment, monthly savings and break-even of refinancing.
Assets minus debts with itemized lists.
Sales commission from amount and percent rate.
Max home price from income, debts and rate.
Compound annual growth rate of an investment.
True loan rate from the monthly payment.
Money saved by quitting smoking.
Weekly pay with time-and-a-half.
Units to cover fixed costs.
Gain from buy/sell prices with fees.
Movers vs DIY truck estimate.
Net card rewards per year.
New salary and annual gain.
Years to double your money.
Decode cron schedules with next run times.
Estimate download/upload durations across internet speeds (Mbps, Gbps, MB/s) with real-world overhead.
Convert between Decimal, Hexadecimal, Binary, Octal, and encode/decode UTF-8 Base64 strings.
Pretty-print, minify and validate JSON with error hints.
Bulk version-4 UUIDs with crypto randomness.
SHA-1/256/384/512 digests of any text, computed locally.
Bits, bytes, KB, MB, GB, TB and PB converter.
Encode and decode URL strings.
4/5-band resistor decoder with visual bands plus V=IR power solver.
Convert colors between HEX, RGB and HSL with live preview.
kWh and cost per day, month and year from wattage and tariff.
Molar mass from a chemical formula.
Range, max height and flight time.
Energy of motion from mass and speed.
Solve C1V1 = C2V2 for the missing value.
Placeholder text by paragraphs.
Solve PV = nRT for the missing variable.
Concentration from mass, molar mass and volume.
Solve mass, volume or density.
Period and frequency from length.
Remaining quantity after decay.
Upper, lower, title and sentence case.
Time and impact speed from height.
Live GitHub-style preview.
Feels-like temperature in wind.
Text to codes and back.
Pixels and REM both ways.
Flesch ease and grade level.
Encode and decode entities.
dB from power or voltage ratio.
Delimited text to JSON.
Text to dots and dashes.
Encode and decode shifts.
Add or subtract days from any calendar date to find project deadlines and milestones.
Calculate working days, billable consulting hours, and exclude custom holiday counts.
Interactive 24-hour visual time matrix to schedule meetings across global timezones.
Hours and minutes between two times, minus breaks, with decimal hours.
Moon phase, illumination and age for any date.
ISO week, day of year and weekday.
Focus sprints with breaks.
Clicks at any tempo.
Mifflin-St Jeor metabolic rate and daily calorie expenditure for fitness goals.
Personalized fluid intake requirements based on body mass and exercise intensity.
US Navy body fat percentage from neck, waist and hip measurements.
MET-based energy burn for walking, running, cycling and more.
Karvonen training zones from age and resting heart rate.
Pace in min/km from distance and time, plus Epley one-rep max.
Daily protein, fat and carbs by goal and calories.
Healthy weight by Devine, Robinson, Miller, Hamwi and Broca formulas.
Date of your goal weight from daily deficit.
Fertile window, ovulation day and due date from cycle data.
Healthy gain range from pre-pregnancy BMI.
Blood alcohol estimate by Widmark.
Distance and burn from daily steps.
Body-fat risk indicator from waist and hips.
Pace per 100 m from swim time.
Category from systolic/diastolic.
Recovery days from zones crossed.
Alcohol by volume from gravity.
Watts from speed and weight.
Trail time by Naismith’s rule.
Daily grams by goal.
Percent correct and letter grade from score.
Jackpot odds and expected value from pool and picks.
Estimate fuel consumption, trip expense, and split payments fairly among road trip passengers.
Scale display resolutions (16:9, 9:16, 4:3, 21:9) with interactive proportional canvas preview.
Add, subtract, multiply and divide fractions with simplification.
Grade point average from courses with credits and letter grades.
Concrete volume and bags, paint liters, tile count with waste.
Cups, spoons and ounces to grams for flour, sugar, butter and more.
Random numbers, dice rolls and coin flips with history.
Solve any leg of V=S/T plus running pace in min/km.
Areas, perimeters, volumes and surfaces of shapes.
Mean, median, mode, min/max and standard deviation.
Quadratic equations and proportions solver.
Dog and cat years into human years.
Words, characters, sentences and reading time of any text.
Mean confidence interval with margin of error.
Count significant figures and round to N digits.
Decimal to normalized scientific and E-notation, both ways.
Slope, line equation, angle and distance from two points.
Find the missing side of a right triangle.
Log of any base, natural ln, log10 and log2.
Powers with positive, negative and fractional exponents.
Respondents needed for your margin of error.
Slab volume and bags needed.
Lumber volume in board feet.
Greatest divisor and least multiple.
Numbers to numerals and back.
4×8 ft sheets for your walls, waste included.
Cubic yards from length, width and depth.
Area by base-height or Heron, plus perimeter.
Determinant of 2×2 and 3×3 matrices.
Shingle bundles from roof size and pitch.
Posts and pickets from length.
Steps, riser and run from total height.
Rolls from wall size with waste.
Ingredient amounts for any servings.
Boards and feet for a wood deck.
Siding squares with waste.
Primality and smallest divisor.
Gallons from wall size and coats.
Exact n! up to 1000.
Simplify ratios and scale values.
Floor tiles with waste.
nCr and nPr exactly.
Bricks and courses for a wall.
Grounds and water for your brew.
