Newest Calculators

Physics and Chemistry

Molarity Calculator

Calculate molarity, moles, solution volume, solute mass, and dilution values with automatic chemistry unit conversions using this free online calculator.

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Physics and Chemistry

Ideal Gas Law Calculator

Solve pressure, volume, moles, or temperature using PV = nRT with automatic unit conversion in this fast, free Ideal Gas Law Calculator.

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Electrical and Energy

Electrical Horsepower Calculator

Calculate electrical horsepower from voltage, current, power factor, phase, and efficiency for DC, single-phase, and three-phase circuits.

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Electrical and Energy

RC Time Constant Calculator

Calculate RC time constant, capacitor charge and discharge voltage, cutoff frequency, and response time with automatic unit conversions.

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Electrical and Energy

Inductor Calculator

Calculate inductive reactance, stored energy, inductance, and RL time constant with instant unit conversions using this free online inductor calculator.

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Electrical and Energy

Parallel Resistor Calculator

Calculate equivalent resistance for parallel resistors in ohms, kilo-ohms, or mega-ohms. Add voltage to find total current, power, and branch currents.

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Electrical and Energy

Series Resistor Calculator

Calculate total resistance, circuit current, voltage drops, and resistor power for series circuits with mixed ohm, kilo-ohm, and mega-ohm values.

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Electrical and Energy

Battery Charge Time Calculator

Estimate battery charging time from capacity, voltage, starting charge, target charge, charger amps or watts, efficiency, and charging taper.

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Electrical and Energy

Battery Capacity Calculator

Calculate required battery capacity in Ah, Wh, and kWh using load power, runtime, voltage, efficiency, depth of discharge, ageing, and reserve.

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Electrical and Energy

Solar Battery Size Calculator

Calculate solar battery bank size in kWh and Ah using daily energy use, backup days, voltage, depth of discharge, efficiency, and reserve.

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Electrical Calculators

Generator Size Calculator

Calculate the right generator size in kW and kVA using appliance loads, starting watts, power factor and a safety margin for home or business use.

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Electrical Calculators

Appliance Energy Cost Calculator

Estimate appliance electricity use and running cost by wattage, usage time, quantity, standby power, duty cycle, tariff, and carbon factor.

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Electrical Calculators

Circuit Breaker Size Calculator

Calculate a recommended circuit breaker size from load current or power. Supports DC, single-phase, three-phase, continuous loads and standard ratings.

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Electrical Calculators

Transformer Calculator

Calculate transformer voltage, current, turns ratio, winding turns, VA rating, real power, efficiency loss, and single- or three-phase load current.

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Electrical Calculators

LED Resistor Calculator

Calculate the correct resistor for single LEDs, series strings, or parallel branches. Get a standard resistor value, wattage, current, and circuit details.

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Chemistry Calculators

Thermal Expansion Calculator

Calculate linear, area, and volume thermal expansion using temperature change, original size, and expansion coefficient with accurate results.

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Chemistry Calculators

Heat Transfer Calculator

Calculate heat transfer rate through conduction, convection, or overall heat transfer using temperature, area, conductivity, thickness, and time.

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Chemistry Calculators

Specific Heat Calculator

Calculate specific heat, heat energy, mass, temperature change, or final temperature with unit conversions, material presets, formulas, and steps.

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Chemistry Calculators

Refractive Index Calculator

Calculate refractive index using light speed or Snell's law. Get instant, accurate results with formulas, examples, explanations, and FAQs.

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Chemistry Calculators

Decibel Calculator

Calculate sound intensity, pressure, power ratios, combined noise levels, and distance-based decibel changes with this free dB calculator.

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Chemistry Calculators

Sound Intensity Calculator

Calculate sound intensity, sound power, distance, and decibel level using accurate acoustic formulas with this free online calculator.

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Chemistry Calculators

Wave Period Calculator

Calculate wave period from frequency, wavelength and speed, or total time and cycles. Get accurate results in seconds, milliseconds, and more.

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Chemistry Calculators

Wave Frequency Calculator

Calculate wave frequency, period, wavelength, wave speed and angular frequency instantly with accurate formulas and multiple unit options.

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Chemistry Calculators

Angular Velocity Calculator

Calculate angular velocity from angle, time, RPM, frequency, period, or linear speed. Convert results to rad/s, deg/s, RPM, and Hz.

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