# Power

Browse 36 online Power tools for working with power-related formats and operations in your browser. Text inputs are not stored, and uploaded files are deleted after 6 hours.

> Canonical page: https://elysiatools.com/en/tags/power

## Overview

Explore 36 Power tools for processing power-related files and data through a browser-based interface, with no software installation required.

## Frequently asked questions

### What can I do with Power tools?

Power tools support a range of power-related file and data operations, including processing, conversion, validation, and management where available.

### Do I need to install software to use these tools?

No. You can access the tools through your browser, while processing runs on Elysia Tools servers.

### How is my data handled?

Text inputs are not stored. Uploaded files are automatically deleted after 6 hours.

## Tools

- [A/B Test Significance Calculator](https://elysiatools.com/en/tools/ab-test-significance-calculator): Compute conversion-rate or mean differences, 95%/99% confidence intervals, two-sided p-values (Z-test for proportions, Welch t for continuous metrics), lift, sample size for 80%/90% power, recommended experiment days, plus sequential-testing and Bonferroni multiple-comparison warnings.
- [Audio Hum Removal](https://elysiatools.com/en/tools/audio-hum-removal): Remove electrical hum (50/60Hz and harmonics) from audio
- [Capacitor Reactive Power Calculator (Q_c = 2πfCU²)](https://elysiatools.com/en/tools/capacitor-reactive-power): Compute the reactive power produced by a known capacitor: Q_c = 2π·f·C·U². Supports single-phase, three-phase star (Y) and delta (Δ) connections. Returns Q_c in var/kvar, capacitive reactance Xc, and capacitor current Ic. Complementary to the power-factor-correction tool (which sizes a capacitor for a target cosφ).
- [COP Calculator (Coefficient of Performance, COP = Q_c / W)](https://elysiatools.com/en/tools/cop-calculator): Compute the Coefficient of Performance (COP) of a chiller / heat pump: COP = Q_c / W, where Q_c is the cooling capacity and W the work input (both in consistent power units; COP is dimensionless). Three modes: solve COP (given Q_c and W), solve cooling capacity (given COP and W), or solve input power (given COP and Q_c). Capacity in W/kW/BTU·h⁻¹/ton/kcal·h⁻¹, power in W/kW/hp; all converted to W internally.
- [Cycling Power Calculator](https://elysiatools.com/en/tools/cycling-power): Calculate cycling power output and energy expenditure
- [DC Motor Back-EMF & Torque Calculator (E=kω, T=kI)](https://elysiatools.com/en/tools/dc-motor-back-emf): Compute the back-EMF and electromagnetic torque of a DC motor from its machine constant: E=k·ω, T=k·I. In SI units the back-EMF constant equals the torque constant (k_e=k_t=k, V·s/rad=N·m/A). Also returns the mechanical (air-gap) power P=T·ω=E·I. Speed accepted in rad/s or RPM.
- [Decibel Calculator (Power Ratio, Voltage Ratio, dBm/dBu/dBV)](https://elysiatools.com/en/tools/decibel-calculator): Convert between ratios and decibels (10·log power, 20·log amplitude), and across absolute units dBm/dBW/dBV/dBu/dBFS/SIL
- [Drag Force Calculator (F_D = ½·ρ·v²·C_D·A)](https://elysiatools.com/en/tools/drag-force-calculator): Compute the drag force on a body in a fluid stream: F_D = ½·ρ·v²·C_D·A (N), where ρ is the fluid density, v the free-stream velocity, C_D the drag coefficient (shape- and Reynolds-dependent), and A the reference (frontal projected) area. A built-in shape library supplies typical high-Re C_D values: sphere 0.47, hemisphere 0.42, long cylinder 0.81, disk/flat plate 1.17, cube 1.05, streamlined airfoil 0.04, long streamlined ellipsoid 0.07, cone 0.50; or choose 'Custom' to enter C_D directly. Optionally, with dynamic viscosity μ and characteristic length L, the Reynolds number Re = ρ·v·L/μ is computed, and the power dissipated by drag P = F_D·v (W). Density in kg/m³/g/cm³, velocity in m/s/km/h, area in m²/cm²/mm², length in m/cm/mm.
- [Electricity Calculator](https://elysiatools.com/en/tools/electricity-calculator): Calculate electricity costs based on power consumption and usage time
- [Heat Radiation Calculator (Stefan-Boltzmann Law, Q=εσA·T⁴)](https://elysiatools.com/en/tools/heat-radiation-calculator): Compute thermal radiation from a blackbody/grey body (Stefan-Boltzmann law): blackbody emissive power E_b = σ·T⁴ (W/m²), total radiated power Q_rad = ε·σ·A·T⁴ (W); with an optional surrounding temperature T₀ it also computes the net radiative exchange Q_net = ε·σ·A·(T⁴-T₀⁴) (W). σ = 5.670374419e-8 W/(m²·K⁴); ε is the emissivity (0 < ε ≤ 1, blackbody ε=1); T is the ABSOLUTE temperature (K) — °C and °F are first converted to K (this is an absolute temperature, not a difference); A is the radiating area. Area in m²/cm².
- [HP to KW](https://elysiatools.com/en/tools/hp-to-kw): Convert horsepower to kilowatts with configurable decimal precision
- [HP to Watt](https://elysiatools.com/en/tools/hp-to-watt): Convert horsepower to watts with configurable decimal precision
- [Inflation Calculator](https://elysiatools.com/en/tools/inflation-calculator): Calculate the effect of inflation on purchasing power and future value of money
- [KW to HP](https://elysiatools.com/en/tools/kw-to-hp): Convert kilowatts to horsepower with configurable decimal precision
- [KW to MW](https://elysiatools.com/en/tools/kw-to-mw): Convert kilowatts to megawatts with configurable decimal precision
- [KW to Watt](https://elysiatools.com/en/tools/kw-to-watt): Convert kilowatts to watts with configurable decimal precision
- [LED Series Resistor Calculator](https://elysiatools.com/en/tools/led-resistor-calculator): Compute the current-limiting resistor for LEDs in series with power, nearest standard value and wattage rating
- [Mechanical Efficiency Calculator](https://elysiatools.com/en/tools/mechanical-efficiency-calculator): Calculate the efficiency of a mechanical transmission (gearbox, belt, chain, etc.). η = P_out / P_in, returning the efficiency percentage and the power loss P_loss = P_in − P_out.
- [Motor Efficiency Calculator (η = P_out / P_in)](https://elysiatools.com/en/tools/motor-efficiency-calculator): Compute motor efficiency η = P_out / P_in. Supports electrical input (single-phase U·I·cosφ or three-phase √3·U·I·cosφ) or direct P_in; output power can be derived from a loss breakdown (copper+iron+rotor copper+mechanical+stray) or supplied directly.
- [MW to KW](https://elysiatools.com/en/tools/mw-to-kw): Convert megawatts to kilowatts with configurable decimal precision
- [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
- [Power Calculator](https://elysiatools.com/en/tools/power-calculator): Raise a base to any real exponent, with optional scientific notation and verification details
- [Power Factor Correction Calculator](https://elysiatools.com/en/tools/power-factor-correction): Size the shunt capacitor needed to raise the power factor: C = P·(tanφ₁ − tanφ₂)/(2π·f·U²). Returns compensated reactive power Qc, capacitive reactance Xc, capacitor current Ic, and the required capacitance in F/μF.
- [Power Transmission Efficiency Calculator](https://elysiatools.com/en/tools/power-transmission-efficiency): Calculate the overall efficiency of a multi-stage transmission. η_total = η₁·η₂·…·ηₙ. Enter one stage efficiency per line (decimal, e.g. 0.98). Optionally add an input power to get the total loss and per-stage output power.

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