Compare calculators
Both calculators run independently — change the inputs on either side to compare results.
Electrical
LED Series Resistor Calculator
Finds the correct series resistor value and power rating to safely drive one or more LEDs in series from a given supply voltage. Use it whenever you connect LEDs to a voltage source without a dedicated driver.
Fill in the required fields to see your result.
Electrical
Transformer Sizing Calculator
Determine the minimum transformer kVA rating needed for a given electrical load, accounting for demand factor, power factor, safety margin, and ambient temperature derating. Use this when specifying or replacing distribution transformers on new or existing electrical systems.
Fill in the required fields to see your result.
Key differences
| LED Series Resistor Calculator | Transformer Sizing Calculator | |
|---|---|---|
| Category | Electrical | Electrical |
| Inputs required | 4 | 5 |
| Result | Series Resistance (Ω) | Required Transformer Size (kVA) |
| What it does | Finds the correct series resistor value and power rating to safely drive one or more LEDs in series from a given supply voltage. Use it whenever you connect LEDs to a voltage source without a dedicated driver. | Determine the minimum transformer kVA rating needed for a given electrical load, accounting for demand factor, power factor, safety margin, and ambient temperature derating. Use this when specifying or replacing distribution transformers on new or existing electrical systems. |