Ohm's Law Calculator

Science & Engineering

V=IR — solve any two of voltage, current, resistance

Quick Answer

Ohm's Law Calculator: V=IR — solve any two of voltage, current, resistance. V = I × R · I = V ÷ R · R = V ÷ I.

Known quantities (pick any two)

Voltage (V)

Resistance (Ω)

Voltage

220 V

Current (solved)

2.2 A

Resistance

100 Ω

Power (solved)

484 W

Solution steps

1Known: V = 220 V, R = 100 Ω
2V = 220 V, I = 2.2 A
3R = 100 Ω, P = 484 W
4Verified: V = I × R and P = V × I

Energy note: running 1 hour consumes 0.484 kWh; at 0.55 CNY/kWh that's ≈ 0.266 CNY/hour.

Ohm's law wheel (12 formulas)

Solve for	From I,R	Alt 1	Alt 2
V =	I × R	P / I	√(P × R)
I =	V / R	P / V	√(P / R)
R =	V / I	V² / P	P / I²
P =	V × I	I² × R	V² / R

💡 Ohm's law applies to ohmic (resistive) devices. Motors, LEDs and switching power supplies are non-linear — their effective resistance changes with voltage.

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How to Use

Enter known quantities: fill values and confirm units in the Ohm's Law Calculator.
Instant solution: unknowns solve live with the formula shown transparently.
Use constant/material tables: standard physical constants and material data are listed on this page.
Compare conditions: change inputs to compare scenarios.

Key Points

Ohm's Law Calculator is a free online science & engineering tool — open and use, no sign-up.
All calculations run locally in your browser; your data never leaves the device.
Key capability: V=IR — solve any two of voltage, current, resistance.
Results come with formulas and reference tables so you can verify every number.

Formula & How It Works

Ohm's law

V = I × R · I = V ÷ R · R = V ÷ I

FAQ

How do I use the Ohm's Law Calculator?

Open the page and fill in the input fields — results update automatically. V=IR — solve any two of voltage, current, resistance.

Are the results accurate?

Yes. Standard formulas and conversion factors are used and verified.

Is it free? Do I need to sign up?

Completely free. No registration, login or download required.

Does it work on mobile?

Yes. The responsive design works on phones, tablets and desktops.

Is my data saved?

No. Everything runs locally in your browser.

Related Guides

Source & Updates

Based on CODATA recommended constants and standard physics formulas. Last updated: 2025-07

Last updated: 2026-08-04

Formulas and content on this page are reviewed by the YiJianSuan team. For reference only — official sources prevail.

Cite this page: YiJianSuan. Ohm's Law Calculator[EB/OL]. https://www.yijiansuan.com/en/c/science/ohm

Results provided by this tool are for reference only and do not constitute professional advice.