GALAXY OF TOOLS

SCIENCE SECTOR · 56 TOOLS

Free Science & Engineering Calculators

Matrices, equations, calculus, physics and electronics calculators, chemistry, statistics and logic tools. 56 free tools, no sign-up.

Maths7

Physics & electronics35

LED Resistor CalculatorFind the series resistor for one or many LEDs, the next standard E-series value and its power rating.Science & EngineeringBattery Runtime CalculatormAh, Ah or Wh and load → hours; inverter and UPS backup presets, efficiency, DoD, Peukert, reverse and charge time.Science & EngineeringTorque CalculatorSolve τ = F·r·sinθ for any variable in N·m, lb·ft or kgf·m, convert power ↔ torque ↔ rpm; bolt torque.Science & EngineeringWire Gauge CalculatorAWG ↔ mm² ↔ diameter, typical ampacity, voltage drop for copper or aluminium, and the gauge for a maximum drop.Science & EngineeringGear Ratio CalculatorTeeth counts → ratio, output RPM and torque for simple or compound gears, belts, chains and bike gearing.Science & EngineeringResistor Color Code CalculatorRead 4, 5 and 6-band resistor colours, convert a value back to bands, decode SMD 3/4-digit and EIA-96 codes.Science & EngineeringProjectile Motion CalculatorLaunch speed, angle, height and gravity → range, max height, flight time, impact velocity, trajectory table and graph.Science & EngineeringIdeal Gas Law CalculatorSolve PV = nRT for pressure, volume, moles or temperature in any units, with density and the working.Science & EngineeringCable Size CalculatorFind the smallest standard cable size (mm²) for a load in kW or amps, length, voltage and allowed voltage drop.Science & EngineeringCapacitor Code CalculatorDecode 3-digit codes, tolerance, voltage and X7R-style codes; series/parallel, charge, energy, RC and RL time constants.Science & EngineeringkVA to kW ConverterConvert kVA, kW, kVAR and amps for single- and three-phase supplies at any power factor, with generator sizing.Science & EngineeringTap Drill Size Calculator & ChartTap drill for metric, UNC and UNF threads at any percentage of thread, with the nearest standard drill and a chart.Science & Engineering555 Timer CalculatorAstable frequency, duty and high/low times or monostable pulse width from R and C, with solve-for modes.Science & EngineeringPsychrometric CalculatorHumidity ratio, dew point, wet bulb, enthalpy, specific volume and vapour pressure from two air properties.Science & EngineeringBelt Length CalculatorBelt length for two or three pulleys, or the centre distance for a given belt, with timing-belt tooth counts.Science & EngineeringReactance & Resonance CalculatorCapacitive and inductive reactance, series or parallel RLC impedance and phase, LC resonant frequency, Q and bandwidth.Science & EngineeringSheet Metal Bend Allowance CalculatorBend allowance, bend deduction, setback and flat length for sheet metal, with or without a K-factor.Science & EngineeringHardness Conversion CalculatorApproximate steel hardness conversions between Rockwell C and B, Vickers, Brinell and tensile strength.Science & EngineeringCutting Speed, Feed & RPM CalculatorSpindle RPM, feed rate and machining time for turning, drilling and milling, with starting speeds by material.Science & EngineeringMotor Full-Load Current CalculatorMotor full-load amps from kW or HP, voltage, power factor and efficiency, with the working shown.Science & EngineeringO-Ring Size CalculatorCheck O-ring squeeze, stretch and gland fill for a groove, with AS568 and ISO cross-sections in mm.Science & EngineeringPipe Flow & Pressure Drop CalculatorPressure drop, velocity and flow in a pipe by Darcy–Weisbach (Colebrook), Hazen–Williams or Manning, with fittings.Science & EngineeringConduit Fill CalculatorPercentage fill of EMT, IMC, RMC or PVC conduit for mixed THHN, XHHW and THW wires against the NEC 53/31/40% limits.Science & EngineeringMoment of Inertia (Section Properties) CalculatorArea moment of inertia, section modulus and radius of gyration for beams and composite shapes.Science & EngineeringPower Factor Correction CalculatorCapacitor kVAR and µF to raise a load to a target power factor, with currents before and after, for 1- or 3-phase.Science & EngineeringReynolds Number CalculatorReynolds number and laminar or turbulent regime for pipe or plate flow, with water and air properties by temperature.Science & EngineeringSpring Rate CalculatorCompression spring rate, load, shear stress and solid height from wire and coil dimensions.Science & EngineeringPump Power CalculatorHydraulic power, shaft power, motor size and running cost for a pump from flow, head or pressure and efficiency.Science & EngineeringHydraulic Cylinder Force CalculatorPush and pull force, extend and retract speed and oil volume from bore, rod, pressure and pump flow.Science & EngineeringTransformer kVA Sizing CalculatorSize a transformer from your load and find full-load amps on both sides, with Indian and US standard ratings.Science & EngineeringBusbar Size CalculatorCopper or aluminium flat busbar size for a current rating, with derating, short-circuit area and heat loss.Science & EngineeringISO Fit Tolerance CalculatorUpper and lower limits, clearance or interference for ISO 286 fits such as H7/g6, H7/p6 or any custom class.Science & EngineeringSteam Table CalculatorSaturated, superheated and compressed water properties by temperature or pressure, in SI or US units.Science & EngineeringShort-Circuit Current CalculatorTransformer secondary fault current from kVA, voltage and %impedance, with source impedance and peak current.Science & EngineeringLMTD / Heat Exchanger CalculatorLog mean temperature difference for counter, parallel and shell-and-tube flow, then area, duty or U from Q = U·A·F·LMTD.Science & Engineering

Chemistry6

Statistics5

Logic & digital3

Maths, physics, electronics, chemistry and statistics, worked step by step

Homework, lab reports and workshop jobs share a need: a calculation done correctly, with the working shown. These free science and engineering tools do exactly that, in your browser, with nothing uploaded and no login. On the maths side, the matrix calculator adds, multiplies, transposes and inverts matrices, the determinant calculator expands along a row so you can follow it, the equation solver handles linear, quadratic and simultaneous equations, the derivative calculator and integral calculator show each rule applied, and the function grapher plots several functions on one set of axes.

For physics and electronics there is a projectile motion calculator with range, height and flight time, a resistor colour code calculator and capacitor code calculator for reading components, a 555 timer calculator for astable and monostable circuits, a battery runtime calculator, a wire gauge calculator that picks AWG or mm² for a current and run length, and gear ratio and torque calculators for mechanical work. The older Ohm’s law and voltage calculators live here too.

Chemistry students get a molar mass calculator that parses a formula and lists each element, a dilution calculator for C1V1 = C2V2, a pH calculator for strong and weak acids and bases, a chemical equation balancer and the periodic table for reference. Every result can be copied as plain text or LaTeX for a report.

Statistics, logic and tools for writing it up

Using the calculators well

  • Read the steps, not just the answer. The derivative, integral, determinant and equation balancer all show their working so the method is clear before an exam.
  • Keep units consistent. The physics and electrical calculators let you choose units on each field and convert internally; mixing millimetres and inches in a torque calculation is the usual mistake.
  • Wire gauge results follow the ampacity tables in common electrical codes for copper at room temperature. Longer runs are sized for voltage drop; always check against the code that applies where you are.
  • Statistical tests assume certain things about the data (normality, equal variances, independence). The t-test page lists its assumptions and offers the Welch version when variances differ.
  • Numerical integration is used when a closed-form result does not exist, and the page says so and gives the estimated error.

Science & Engineering: frequently asked questions

Do the calculators show the working?

Yes. The symbolic tools (derivatives, integrals, determinants, equation solving, balancing) list each step and the rule applied, and the numeric ones show the formula with your values substituted, so you can check them or copy them into a report.

How large a matrix can I solve?

The matrix and determinant calculators handle any size your browser can hold comfortably; up to about 10×10 is instant and the steps remain readable. Larger systems still solve, but the step-by-step view is summarised.

Which resistor colour bands are supported?

Four, five and six band resistors, including tolerance and temperature-coefficient bands, and the reverse direction: enter a value and get the colours.

Can I trust these for a real electrical installation?

The electronics calculators are correct for the formulas they state, but a real installation must follow your local wiring regulations and be checked by a qualified person. Use them for design, learning and checking, not as a substitute for the code.

Is the pH calculator exact for weak acids?

It solves the equilibrium expression for weak acids and bases from the Ka or Kb you give, and the simplifying approximation is shown alongside the exact root so you can see when they diverge.