Unit Converter & Calculator Hub
Fast, accurate conversions and calculators. Free, no sign-up required.
All categories
- Kilometers to Miles
- Miles to Kilometers
- Meters to Feet
- Kilograms to Pounds
- Pounds to Kilograms
- Ounces to Grams
- Celsius to Fahrenheit
- Fahrenheit to Celsius
- Liters to US Gallons
- US Gallons to Liters
- Square Meters to Square Feet
- Square Feet to Square Meters
- Kilometers Per Hour to Miles Per Hour
- Miles Per Hour to Kilometers Per Hour
- Grams to Cups
- PSI to Bar
- Bar to PSI
Specialty Tools
Hex, RGB, HSL, HSV, CMYK
Binary, Decimal, Hex, Octal
Roman โ Decimal (1โ3999)
JSON, YAML, TOML
Oven to Air Fryer
Subnet calculators, IP converters, password tools, and more for network administrators and IT professionals.
Encoders, decoders, hash generators, and text analysis tools for developers. All processing happens in your browser.
Ingredient Substitution Calculator
Out of butter, eggs, or flour? Find the best cooking substitutes with exact scaled quantities. Supports 30+ ingredients across fats, dairy, sweeteners, flours, and more.
- ๐ง Butter swaps
- ๐ฅ Egg replacements
- ๐พ Flour alternatives
- ๐ฅ Dairy-free options
Popular Converters
Popular Calculators
Calculate monthly payments, total interest, and view amortization schedule.
Calculate tip amount and split the bill between multiple people.
Calculate your Body Mass Index and see your weight category.
Calculate percentages, percentage change, and more.
Add, subtract, multiply, and divide fractions with step-by-step working shown.
Calculate the exact difference between two dates.
Calculate your exact age in years, months, and days, and find out how many days until your next birthday.
Calculate how your investment grows over time with compound interest and optional regular contributions.
Calculate monthly payments, total interest, and total cost on personal loans.
Calculate discount amounts and final prices with percentage or dollar-off discounts.
Convert between annual, monthly, biweekly, weekly, and hourly pay rates.
Calorie and TDEE calculator. Find your Total Daily Energy Expenditure and BMR with Mifflin-St Jeor and Harris-Benedict equations, plus macronutrient breakdown for your caloric goals.
Calculate voltage, current, resistance, or power from any two known values using Ohm's Law and power formulas.
Solve for output voltage or either resistor in a two-resistor divider, with optional load to show the real-world loading effect.
Calculate the current-limiting resistor for an LED or LED chain from supply voltage, forward voltage, and forward current.
How Calcflux Works
Calcflux covers 2,000+ conversion pages across 21 unit categories and 47 calculators for finance, health, engineering, and everyday math. The site is available in 5 languages: English, German, Spanish, French, and Portuguese.
A baker scaling a European recipe from grams to cups can select the exact ingredient (flour, sugar, butter) for a density-accurate result. An engineer converting blueprint measurements from millimeters to inches sees the conversion formula alongside the answer. A traveler checking whether 130 km/h means 80 or 81 mph gets a precise result to 15 significant digits.
Every conversion factor is verified against NIST SP 330 (the International System of Units) and ISO 80000 standards. The formulas are displayed next to every result so you can check the math yourself. All calculations run in your browser using IEEE 754 double-precision arithmetic. No data leaves your device, no account is needed, and there are no tracking cookies.
Why Calcflux?
Precise Results
Conversions verified against NIST and ISO standards with up to 15 significant digits.
Instant Answers
Results appear as you type. No waiting or page reloads.
Privacy First
No tracking cookies, no sign-up required. Your data stays on your device.
Formulas Shown
Every conversion shows the formula so you understand the math, not just the answer.