Free 89 Calculators for Every Need
Browse by Category
Popular Calculators
BMI Calculator
Calculate your Body Mass Index and see your health category
Age Calculator
Calculate your exact age in years, months, and days
P-Value Calculator
Calculate p-values for statistical hypothesis testing
Test Grade Calculator
Calculate your test score and letter grade with customizable grading scale
Annealing Temperature Calculator
Estimate PCR primer annealing temperature (Ta) from primer and target melting temperatures (Tm). Supports °C / °F / K.
Average Percentage Calculator
Calculate simple or weighted average of multiple percentages
Percentage Increase Calculator
Calculate percentage change between two values instantly
Quadratic Equation Solver
Solve quadratic equations with step-by-step solutions and visualizations
Fraction to Percent Calculator
Convert fractions to percentages and vice versa instantly
Grams to Tablespoons Converter
Convert grams to tablespoons for any ingredient instantly. Perfect for cooking and baking with support for multiple ingredients.
Percentage of a Percentage Calculator
Calculate cumulative percentages by multiplying two percentages together
Decimal to Percent Converter
Convert decimal numbers to percentages with real-time bidirectional conversion
Percentage Point Calculator
Calculate the difference between two percentages and understand percentage point vs percentage change
Doubling Time Calculator
Calculate the time required for investments or populations to double given a growth rate
Percent Error Calculator
Calculate the percent error between an observed value and a true value. Learn the formula and get step-by-step calculations for measurement accuracy.
Salary to Hourly Calculator
Convert between hourly wage, annual salary, and other pay periods. Calculate your take-home pay with customizable work hours.
Confidence Interval Calculator
Calculate confidence intervals for population mean or proportion. Supports standard deviation and standard error with customizable confidence levels.
Log Calculator
Calculate logarithms with any base. Enter the number and base to find the logarithm, or solve for any unknown variable in the logarithmic equation.
Atom Calculator
Calculate atomic properties including protons, neutrons, electrons, atomic number and mass number
Electron Configuration Calculator
Get the electron configuration for any element from the periodic table. View atomic number, atomic mass, and valence electrons.
Atomic Mass Calculator
Calculate atomic mass from protons and neutrons. Get atomic mass in various units including atomic mass units (u), kilograms, and more.
Electronegativity Calculator
Calculate electronegativity difference between two elements and determine bond type (ionic, polar covalent, or nonpolar covalent).
Average Atomic Mass Calculator
Calculate the average atomic mass of an element based on the isotopes and their natural abundances.
Board Foot Calculator
Calculate board feet from lumber dimensions. Convert timber volume measurements across different unit systems.
Meet the Creator
Full-time Creator of CalculatorVast
Hey, I'm Frank! I build calculators that actually work. I'll admit to a touch of OCD – each one is put through a relentless testing process (my own minor obsession) to ensure you get a tool you can really rely on. (PS: Meticulously crafted from the ancient city of Xi'an, China.)
Background: Northeastern University
Passion: IT, Programming & Building Reliable Tools