Conversions & Tools Calculators
The metric system is the global standard, but the United States still uses customary units for daily life, and the UK mixes metric and imperial in confusin...
106 calculators available · Updated 2026-06-15
The metric system is the global standard, but the United States still uses customary units for daily life, and the UK mixes metric and imperial in confusing ways. Our conversion calculators bridge the gap with precise, no-ads, no-tracking tools that work offline once loaded. Every conversion uses the official definitions from NIST, BIPM, and ISO 80000.
How to choose the right conversion calculator
Identify what you are converting. Length, weight, temperature, area, volume, time, speed, data, energy, pressure, and angle are the most common categories. Within each, identify the source and target units. For most conversions, just type the value, pick the source unit, and the target unit. The calculator shows the formula and the precise conversion factor. For chained conversions (e.g., miles per gallon to liters per 100 kilometers), use the dedicated fuel economy calculator.
Length, distance, and area
The length converter handles metric (mm, cm, m, km), imperial (in, ft, yd, mi), and nautical (nmi) units. The inch-to-cm and feet-to-meter conversions are the most-used. The area converter handles m², ft², acres, hectares, and square miles. 1 acre = 4,046.86 m² = 0.4047 hectares. 1 hectare = 2.471 acres. For real estate, 1 m² = 10.764 ft² and 1 ft² = 0.0929 m².
Weight, mass, and volume
The weight converter handles metric (mg, g, kg, t), imperial (oz, lb, st, ton), and troy (oz t, lb t) units. 1 kg = 2.20462 lb. 1 lb = 453.592 g. The volume converter handles metric (mL, L, m³), US customary (tsp, tbsp, fl oz, cup, pt, qt, gal), and imperial (UK fl oz, UK gal) units. 1 US gallon = 3.785 L; 1 imperial gallon = 4.546 L. The dry volume converter handles US dry units (pint, quart, peck, bushel) for agriculture.
Temperature and time
The temperature converter handles Celsius, Fahrenheit, Kelvin, and Rankine. The formulas are: °F = (°C × 9/5) + 32; °C = (°F - 32) × 5/9; K = °C + 273.15. The time converter handles seconds, minutes, hours, days, weeks, months, and years, with configurable days-per-month for accurate month conversions. The time zone converter uses the IANA tz database for accurate DST handling.
Data storage, speed, and digital units
The data storage converter uses the binary (1 KiB = 1,024 bytes) convention by default, with a toggle to the decimal (1 KB = 1,000 bytes) convention used by storage manufacturers. 1 GB (decimal) = 0.931 GiB (binary). The data transfer speed converter handles bps, kbps, Mbps, Gbps, and their byte counterparts. The download time calculator estimates how long a file takes to transfer at a given connection speed.
Energy, pressure, and fuel economy
The energy converter handles joules, calories, watt-hours, BTU, and kWh. 1 kWh = 3.6 MJ = 3,412 BTU. The pressure converter handles pascals, psi, bar, atmospheres, mmHg, and torr. 1 atm = 101.325 kPa = 14.696 psi. The fuel economy converter handles mpg (US), mpg (UK), L/100km, and km/L. Converting US mpg to L/100km: divide 235.215 by the mpg value. Converting L/100km to US mpg: divide 235.215 by the L/100km value.
Most Popular Conversions & Tools Calculators
All Conversions & Tools Calculators (106)
Unit Converter
Length, weight, and temperature.
Speed / Distance / Time
Solve for the missing value.
Hours
Hours worked between two times.
Date
Difference between two dates.
Screen Size
PPI, dimensions, aspect ratio.
Currency Conversion Calculator with Fees
Calculate currency conversions with transfer fees and compare exchange rates across major currencies.
Exact Age Calculator - Years, Months, Days, Hours
Calculate your exact age in years, months, days, hours, and minutes between two dates.
Date Difference Calculator - Days Between Dates
Calculate the exact difference between two dates in multiple units including workdays and weekends.
Vacation Budget Calculator - Trip Cost Estimator
Plan and estimate your total vacation costs including flights, accommodation, food, and activities.
Moving Cost Calculator - Estimate Relocation Expenses
Estimate your total moving costs including transport, packing, insurance, and storage.
Wedding Budget Calculator - Plan Your Big Day
Plan and estimate your total wedding costs by category with guest-count-based projections.
Baby Cost Calculator - Child Raising Expenses
Estimate the total cost of raising a child with projections by category and year.
College Cost Calculator - Plan Education Savings
Estimate future college costs and determine how much you need to save monthly to cover them.
Retirement Lifestyle Calculator - Will You Have Enough?
Project your retirement fund growth and determine if your savings will support your desired lifestyle.
Car Total Cost Calculator - True Ownership Cost
Calculate the true cost of owning a car including depreciation, insurance, fuel, maintenance, and financing.
Fuel Cost Trip Calculator - Road Trip Gas Expenses
Calculate the fuel cost for your road trip including gas, tolls, and parking split among passengers.
Electricity Cost Calculator - Monthly & Annual Bills
Estimate your monthly and annual electricity bills with seasonal variations and solar offset options.
Water Bill Calculator - Monthly & Annual Water Costs
Estimate your monthly and annual water bills based on household usage, rates, and irrigation needs.
Temperature Converter
Convert temperatures between Celsius, Fahrenheit, and Kelvin instantly with visual comparison.
Length Converter — mm, cm, m, km, in, ft, yd, mi | CalcxApp
Convert between metric and imperial length units instantly.
Weight Converter — mg, g, kg, oz, lb, st | CalcxApp
Convert between metric and imperial weight units instantly.
Volume Converter — mL, L, gal, qt, pt, cup, fl oz | CalcxApp
Convert between metric and imperial volume units instantly.
Speed Converter — m/s, km/h, mph, knots, Mach | CalcxApp
Convert between m/s, km/h, mph, knots, and more instantly.
Time Converter — ms, sec, min, hr, day, week, month, year
Convert between milliseconds, seconds, minutes, hours, days, weeks, months, and years.
Data Storage Converter
Convert between bits, bytes, KB, MB, GB, TB, PB, KiB, MiB, GiB, TiB instantly.
Cooking Converter — Cups, Tablespoons, mL, Ounces | CalcxApp
Convert between cups, tablespoons, teaspoons, milliliters, ounces, and more
Shoe Size Converter — US, UK, EU, CM | CalcxApp
Convert shoe sizes between US, UK, EU, and cm measurements
Dress Size Converter
Convert dress sizes between US, UK, EU, and international sizing
Bra Size Converter & Calculator — US, UK, EU | CalcxApp
Find your bra size from measurements with conversions to 7 international sizing systems.
Ring Size Converter — US, UK, EU, mm | CalcxApp
Convert ring sizes between US, UK, EU, and millimeter measurements
Password Generator — Strong Random Passwords | CalcxApp
Generate strong, random passwords and check their strength
Color Converter — HEX, RGB, HSL, CMYK | CalcxApp
Convert colors between HEX, RGB, HSL, and CMYK formats
Timezone Converter — World Time Converter | CalcxApp
Convert time between different timezones around the world
Countdown Calculator — Days, Hours & Minutes to Any Date
Calculate the exact time remaining until any date and time
Work Hours & Earnings Calculator | CalcxApp
Calculate earnings based on hourly rate, hours worked, and schedule
Half-Life Calculator — Radioactive Decay | CalcxApp
Calculate remaining substance amount using the half-life decay formula
Dilution Calculator — C1V1 = C2V2 | CalcxApp
Calculate solution dilution volumes using the C1V1 = C2V2 formula
Angle Converter | CalcxApp
Convierte entre grados, radianes y gradianes
Binary Converter | CalcxApp
Convierte entre binario, decimal, octal y hexadecimal
Data Transfer Time Calculator | CalcxApp
Calcula el tiempo de transferencia de datos
Density Converter | CalcxApp
Convierte entre unidades de densidad
Energy Converter — Joules, kWh, BTU, Calories & More
Convierte entre unidades de energía
Force Converter | CalcxApp
Convierte entre unidades de fuerza
Pressure Converter | CalcxApp
Convierte entre unidades de presión
Torque Converter | CalcxApp
Convierte entre unidades de torque
EV Savings Calculator — Electric vs Gas Car Cost Comparison
Compare the total cost of ownership between an electric vehicle and a gas-powered car.
Internet Speed Calculator - How Much Speed Do You Need?
Find the ideal internet speed for your household based on usage patterns and number of users.
Subscription Audit Calculator | Find Wasted Money
Audit your subscriptions, find waste, and see the true annual cost of your digital life.
Gift Budget Calculator - Plan Holiday and Birthday Gift Spe…
Plan your gift spending with a detailed breakdown by recipient, wrapping, shipping, and cards.
Holiday Budget Calculator — CalcxApp
Plan your holiday travel budget with detailed breakdown by category: travel, accommodation, food, activities, and gifts.
Birthday Party Calculator — CalcxApp
Plan your birthday party budget with itemized costs for venue, food, cake, decorations, and entertainment.
Home Repair Calculator — CalcxApp
Estimate home repair costs including labor, materials, and permits based on repair type and scope.
International Bra Size Converter
Convert bra sizes between US, UK, EU, French, Italian, Australian, Japanese, and Brazilian sizing systems instantly with accurate international conversion charts.
Bra Cup Size Equivalent Chart — DD=E, DDD=F, DDDD=G
Convert between US, UK, EU, and French bra cup letter naming systems. Clear up the DD = E, DDD = F, DDDD = G confusion.
Bra Size Chart — Interactive US, UK, EU, FR, IT, AU, JP
Interactive bra size chart with international sizing systems. View, filter, and convert bra sizes across US, UK, EU, FR, IT, AU, and JP systems.
Bra Size to Swimwear Converter
Convert your bra size to swimwear and bikini sizing for major brands including Victoria's Secret, Target, H&M, ASOS, Zaful, and Aerie.
Celsius to Fahrenheit Converter | CalcxApp
Quick and accurate celsius to fahrenheit calculator with visual charts and detailed tables.
Fahrenheit to Celsius Converter | CalcxApp
Quick and accurate fahrenheit to celsius calculator with visual charts and detailed tables.
Kelvin to Celsius / Fahrenheit Converter | CalcxApp
Quick and accurate kelvin to celsius calculator with visual charts and detailed tables.
Inches to Centimeters Converter | CalcxApp
Quick and accurate inches to cm calculator with visual charts and detailed tables.
Centimeters to Inches Converter | CalcxApp
Quick and accurate cm to inches calculator with visual charts and detailed tables.
Feet to Meters Converter — ft → m | CalcxApp
Quick and accurate feet to meters calculator with visual charts and detailed tables.
Meters to Feet Converter — m → ft | CalcxApp
Quick and accurate meters to feet calculator with visual charts and detailed tables.
Yards to Meters Converter | CalcxApp
Quick and accurate yards to meters calculator with visual charts and detailed tables.
Miles to Kilometers Converter | CalcxApp
Quick and accurate miles to km calculator with visual charts and detailed tables.
Kilometers to Miles Converter | CalcxApp
Quick and accurate km to miles calculator with visual charts and detailed tables.
Kilograms to Pounds Converter | CalcxApp
Quick and accurate kg to lbs calculator with visual charts and detailed tables.
Pounds to Kilograms Converter | CalcxApp
Quick and accurate lbs to kg calculator with visual charts and detailed tables.
Ounces to Grams Converter | CalcxApp
Quick and accurate ounces to grams calculator with visual charts and detailed tables.
Grams to Ounces Converter | CalcxApp
Quick and accurate grams to ounces calculator with visual charts and detailed tables.
Stones to Kilograms Converter | CalcxApp
Quick and accurate stones to kg calculator with visual charts and detailed tables.
Tons to Kilograms Converter | CalcxApp
Quick and accurate tons to kg calculator with visual charts and detailed tables.
Gallons to Liters Converter | CalcxApp
Quick and accurate gallons to liters calculator with visual charts and detailed tables.
Liters to Gallons Converter | CalcxApp
Quick and accurate liters to gallons calculator with visual charts and detailed tables.
Cups to mL Converter — Cooking Volume | CalcxApp
Quick and accurate cups to ml calculator with visual charts and detailed tables.
Fluid Ounces to mL Converter | CalcxApp
Quick and accurate fluid ounces to ml calculator with visual charts and detailed tables.
Tablespoons to Teaspoons Converter | CalcxApp
Quick and accurate tablespoons to teaspoons calculator with visual charts and detailed tables.
MPH to KPH Converter | CalcxApp
Quick and accurate mph to kph calculator with visual charts and detailed tables.
KPH to MPH Converter | CalcxApp
Quick and accurate kph to mph calculator with visual charts and detailed tables.
Meters per Second to KPH Converter | CalcxApp
Quick and accurate m/s to kph calculator with visual charts and detailed tables.
Knots to MPH Converter — Sailing & Aviation | CalcxApp
Quick and accurate knots to mph calculator with visual charts and detailed tables.
Square Feet to Square Meters Converter | CalcxApp
Quick and accurate square feet to square meters calculator with visual charts and detailed tables.
Square Meters to Square Feet Converter | CalcxApp
Quick and accurate square meters to square feet calculator with visual charts and detailed tables.
Acres to Hectares Converter — Land Area | CalcxApp
Quick and accurate acres to hectares calculator with visual charts and detailed tables.
Hectares to Acres Converter — Land Area | CalcxApp
Quick and accurate hectares to acres calculator with visual charts and detailed tables.
Bytes to KB Converter — File Size | CalcxApp
Quick and accurate bytes to kb calculator with visual charts and detailed tables.
KB to MB Converter — File Size | CalcxApp
Quick and accurate kb to mb calculator with visual charts and detailed tables.
MB to GB Converter — File Size | CalcxApp
Quick and accurate mb to gb calculator with visual charts and detailed tables.
GB to TB Converter — Storage Size | CalcxApp
Quick and accurate gb to tb calculator with visual charts and detailed tables.
Joules to Calories Converter | CalcxApp
Quick and accurate joules to calories calculator with visual charts and detailed tables.
Calories to Joules Converter | CalcxApp
Quick and accurate calories to joules calculator with visual charts and detailed tables.
kWh to Joules Converter | CalcxApp
Quick and accurate kwh to joules calculator with visual charts and detailed tables.
PSI to Bar Converter | CalcxApp
Quick and accurate psi to bar calculator with visual charts and detailed tables.
Bar to PSI Converter | CalcxApp
Quick and accurate bar to psi calculator with visual charts and detailed tables.
Pascal to PSI Converter | CalcxApp
Quick and accurate pa to psi calculator with visual charts and detailed tables.
Newton to Pound-Force Converter | CalcxApp
Quick and accurate newton to lbf calculator with visual charts and detailed tables.
Degrees to Radians Calculator — π Conversion | CalcxApp
Quick and accurate degrees to radians calculator with visual charts and detailed tables.
Radians to Degrees Calculator — Instant Conversion | CalcxApp
Quick and accurate radians to degrees calculator with visual charts and detailed tables.
Seconds to Minutes Calculator | CalcxApp
Quick and accurate seconds to minutes calculator with visual charts and detailed tables.
Minutes to Hours Calculator | CalcxApp
Quick and accurate minutes to hours calculator with visual charts and detailed tables.
Hours to Days Calculator | CalcxApp
Quick and accurate hours to days calculator with visual charts and detailed tables.
Days to Weeks Calculator | CalcxApp
Quick and accurate days to weeks calculator with visual charts and detailed tables.
Weeks to Months Calculator | CalcxApp
Quick and accurate weeks to months calculator with visual charts and detailed tables.
Months to Years Calculator | CalcxApp
Quick and accurate months to years calculator with visual charts and detailed tables.
Decade Calculator — Years to Decades | CalcxApp
Quick and accurate decade calculator with visual charts and detailed tables.
Centuries Calculator — Years to Centuries | CalcxApp
Quick and accurate century calculator with visual charts and detailed tables.
Frequently Asked Questions
Do you use binary or decimal for data storage? ▾
Both, with a toggle. By default we use binary (1 KiB = 1,024 bytes) which is what operating systems report. Toggle to decimal (1 KB = 1,000 bytes) for storage manufacturer specifications and network speeds.
How do you handle time zones? ▾
Our time zone converter uses the IANA tz database, which accounts for daylight saving time transitions and historical changes. The database is updated quarterly.
Are these conversions exact? ▾
Yes, for unit conversions. The conversion factors are defined exactly by international standards. For calculations involving floating-point, results are accurate to 15-17 significant digits.
Do you convert between metric and imperial cooking units? ▾
Yes. The volume converter handles teaspoons, tablespoons, fluid ounces, cups, pints, quarts, gallons (US and UK), milliliters, and liters with high precision.
Can I use these offline? ▾
Yes. Once the page is loaded, the calculator works without an internet connection. All conversion formulas run in your browser.
Sources & References
The formulas, definitions, and best-practice guidance in these conversions & tools calculators are grounded in the following authoritative sources: