# Force Calculator (F = m·a) Compute force, mass, or acceleration from Newton's second law, with weight on Earth > Canonical page: https://elysiatools.com/en/tools/force-calculator - **Category:** Math & Numbers - **Keywords:** force, mass, acceleration, newton, newtons second law, f=ma, physics, mechanics, dynamics, weight ## Overview Newton's second law relates force, mass, and acceleration. Equations (three-way solver): - Force: F = m · a (N) - Mass: m = F / a - Acceleration: a = F / m Weight on Earth = m · g (g = 9.80665 m/s²). ## Inputs - **Solve For** (select) - **Force (F, N)** (number): leave blank when solving for force - **Mass (m, kg)** (number): leave blank when solving for mass - **Acceleration (a, m/s²)** (number): leave blank when solving for acceleration ## When to use - When solving physics homework problems involving Newton's second law of motion. - When calculating the required force to accelerate a mechanical component of a known mass. - When determining the mass or acceleration of an object when the applied force is known. ## How it works - Select the variable you want to solve for: Force (F), Mass (m), or Acceleration (a). - Enter the values for the other two known variables in their respective fields. - Click calculate to compute the missing value along with the object's weight on Earth based on standard gravity. ## Use cases - Engineering design to determine the motor force needed to move a specific payload. - Physics education for students and teachers verifying dynamics equations. - Aerospace calculations to estimate the acceleration of a drone or rocket model given thrust and mass. ## Frequently asked questions ### What units are used in this calculator? Force is measured in Newtons (N), mass in kilograms (kg), and acceleration in meters per second squared (m/s²). ### How is weight on Earth calculated? Weight is calculated as mass multiplied by Earth's standard gravitational acceleration (g = 9.80665 m/s²). ### Can I calculate mass if I only know the force? No, you must provide both force and acceleration to calculate mass. ### What formula does this tool use to find acceleration? It uses the formula a = F / m, dividing the net force by the mass. ### Does this calculator account for friction or air resistance? No, it calculates net force based on Newton's second law without factoring in external resistive forces. ## Related tools - [Dimensional Analysis Unit Cancellation Tutor](https://elysiatools.com/en/tools/dimensional-analysis-unit-cancellation-tutor): Step-by-step factor-label unit cancellation with inverted-factor diagnosis and optional student-answer checking. - [Kinetic Energy Calculator (KE = ½mv²)](https://elysiatools.com/en/tools/kinetic-energy-calculator): Compute kinetic energy, mass, or velocity from the other two, with momentum and km/h conversion - [Momentum Calculator (p = mv)](https://elysiatools.com/en/tools/momentum-calculator): Compute linear momentum, mass, or velocity from the other two, with kinetic energy and km/h conversion - [Ohm's Law and Power Triangle Calculator](https://elysiatools.com/en/tools/ohms-law-calculator): Solve for two unknowns among Voltage, Current, Resistance and Power from any two given values, with visual triangles and AC power-factor support - [Pressure Calculator & Converter (P=F/A, Pa/kPa/bar/atm/psi)](https://elysiatools.com/en/tools/pressure-conversion): Solve pressure, force, or area from P=F/A, and convert between Pa, kPa, MPa, bar, atm, psi, Torr, inHg, kgf/cm² - [Torque Calculator (τ = rF sinθ)](https://elysiatools.com/en/tools/torque-calculator): Compute torque, force, or lever arm from τ = r·F·sin(θ), with the perpendicular force component shown - [Cable Voltage Drop Calculator](https://elysiatools.com/en/tools/voltage-drop-calculator): Compute cable voltage drop from current, length, conductor size (AWG/mm²) and material, for DC, single-phase and three-phase circuits - [Absolute Value Calculator](https://elysiatools.com/en/tools/absolute-value-calculator): Calculate the absolute value of positive, negative, or decimal numbers and explain the sign relationship ## Samples - [Web Image Processing Python Samples](https://elysiatools.com/en/samples/web-image-processing-python): Web Python image processing examples using PIL/Pillow including reading, saving, resizing, and format conversion - [Android Image Processing Java Samples](https://elysiatools.com/en/samples/android-image-processing-java): Android Java image processing examples including reading/saving images, scaling, and format conversion - [Android Image Processing Kotlin Samples](https://elysiatools.com/en/samples/android-image-processing-kotlin): Android Kotlin image processing examples including reading/saving images, scaling, and format conversion - [Web Image Processing Rust Samples](https://elysiatools.com/en/samples/web-image-processing-rust): Web Rust image processing examples including image read/save, scaling, and format conversion ## Related content - [Physics Classroom and Lab Calculators](https://elysiatools.com/en/hubs/physics-classroom-and-lab-calculators): Compare force, energy, motion, buoyancy, pressure, wave, decibel, and measurement-precision tools in one focused physics study and lab workflow hub. - [Audio Encoding and Format Conversion Tools](https://elysiatools.com/en/hubs/audio-convert): Compare audio format conversion, bitrate changes, sample-rate conversion, codec swaps, and export tools in one hub for delivery and archive workflows. - [Image Format Conversion and Animated Export Tools](https://elysiatools.com/en/hubs/image-convert): Compare image format converters for JPG, PNG, GIF, AVIF, WebP, TIFF, ICO, base64, and animation-friendly exports in one hub. - [JSON Interchange and Format Translation Tools](https://elysiatools.com/en/hubs/json-convert): Compare JSON conversion tools for CSV, YAML, TOML, GraphQL, XML, Markdown, Excel, BSON, EDN, and related structured formats in one hub.