Ohm's Law Triangle

Calculate Voltage, Current, and Resistance Interactively

Tap a section to solve for that value

VIR
V = Voltage I = Current R = Resistance

🔢 Known Values

Amps
Ohms

Unit Reminder:
1,000 mA = 1 Amp
1,000 Ω = 1 kΩ

The value of V is


Formula Used:
V = I × R

🎯 A Simple Example: Lighting an LED

You have a 9V battery and an LED that needs 0.02 Amps (20mA) to glow. You need to know what resistor will keep it from burning out.

Just do this:

1️⃣ Tap the R section of the triangle (since we want to find Resistance).

2️⃣ Enter 9 in the Voltage box.

3️⃣ Enter 0.02 in the Current box.

4️⃣ Look at the Result: You need a 450 Ω resistor! 📐

Pro tip: In the real world, batteries lose voltage as they die. If your circuit stops working, check if the "pressure" (V) has dropped!

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Data Source: Ohm, Die galvanische Kette, mathematisch bearbeitet • Public domain • Solo-developed with AI

Lab Notes

The Trinity of Electricity: Why Ohm's Law is the Builder's Rule

The Secret of Flow: Imagine water flowing through a pipe. Voltage is the "pressure" pushing the water, Current is the "volume" of water moving, and Resistance is the "size of the pipe" fighting against that flow. In 1827, Georg Simon Ohm published his discovery that these three things are perfectly linked. In our Digital Laboratory, we treat this relationship as the absolute law of the land. If you know any two, the third is always predictable. This simple ratio—V = I × R—is the reason your phone doesn't explode when you plug it into the wall!

The Power of the Triangle: Why do we use a triangle? It’s a clever 19th-century memory trick! If you cover the letter you want to find, the remaining letters show you the math. Cover **V**, and you see **I** next to **R** (multiply them). Cover **I**, and you see **V** over **R** (divide them). It is a visual representation of a mathematical identity that has guided everyone from early telegraph operators to modern microprocessor designers.

Engineering the Future: Historically, Ohm’s research was initially ignored because it was "too simple." But as the Industrial Age accelerated, engineers realized they couldn't build a single telegraph line or lightbulb without it. Today, it’s the first thing every robotics hobbyist and electrical engineer learns. We bridge the gap between abstract physics and your workbench by giving you a tool that handles the division so you can focus on the invention.

Bridging Data to the Present Day: In the Lab, we’ve made the classic textbook diagram interactive. As you click through the triangle, you aren't just doing math; you're exploring the balance of a circuit. Whether you're picking the right resistor for an LED, calculating battery draw, or just trying to understand why your toaster gets hot, our calculator provides the rigorous proof that electricity is a perfectly balanced system of ratios.

🐾 From the Lab Cat's High-Resistance Division:

I have Conducted rigorous field tests on Ohm's Law by sitting on various electronic devices.

  • The Heat Factor: Voltage times Current equals Power, which I measure in "belly-warmth." My laptop is currently operating at 45 Watts of nap-efficiency.
  • The Static Trap: I have discovered that my fur has high capacitance but also high resistance. Walking across a wool rug increases my potential energy until I discharge via "nose-boop" to your ear.
  • Wire Logic: Humans use copper wires to move current. I use wires as "unstructured play-surfaces." The resistance of my claws is greater than your insulation.

Current Status: I have achieved 0.0 Amps of movement. My internal battery is charging. 🐈

In short: These tools are for education and curiosity only. Always verify information independently and consult professionals before making important decisions.

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