Compare calculators
Both calculators run independently β change the inputs on either side to compare results.
Electrical
Transformer Calculator
Determine the primary current draw of a transformer given its output voltage, output current, and efficiency. Use this when sizing transformers for power supplies, HVAC systems, or industrial equipment.
Fill in the required fields to see your result.
Electrical
LED Resistor Calculator
Calculate the exact current-limiting resistor value needed to safely power an LED from any supply voltage. Use this whenever wiring LEDs to avoid burning them out from excess current.
Fill in the required fields to see your result.
Key differences
| Transformer Calculator | LED Resistor Calculator | |
|---|---|---|
| Category | Electrical | Electrical |
| Inputs required | 4 | 3 |
| Result | Primary Current (A) | Resistor Value (Ξ©) |
| What it does | Determine the primary current draw of a transformer given its output voltage, output current, and efficiency. Use this when sizing transformers for power supplies, HVAC systems, or industrial equipment. | Calculate the exact current-limiting resistor value needed to safely power an LED from any supply voltage. Use this whenever wiring LEDs to avoid burning them out from excess current. |