Electronics
Voltage Divider Calculator
Design resistor divider networks with confidence. The calculator accounts for load resistance and shows tap voltage and current draw.
Design resistor dividers with load-aware output voltage.
Divider formula
Vout = Vin × (R₂ / (R₁ + R₂))
If a load is attached, the effective lower resistance becomes (R₂ × R_load) ÷ (R₂ + R_load), which the calculator applies automatically.
How to use
- Enter the supply voltage and resistor values.
- Add an optional load resistance to see how it drags down the divider output.
- Review the output voltage, current through the chain, and power for each resistor.
Example
Input: Vin = 12 V, R1 = 4.7 kΩ, R2 = 2.2 kΩ, Load = 10 kΩ
Output: Vout ≈ 3.08 V, Chain current ≈ 1.76 mA
Student-friendly breakdown
This walkthrough emphasizes the most searched ideas for Voltage Divider Calculator: voltage divider calculator, resistor divider calculator, voltage drop calculator resistors, voltage divider with load calculator. Start with the formula above, then follow the guided steps to double-check your work. For quick revision, highlight the givens, plug into the equation, and finish by verifying your units.
Need more support? Use the links below to open the long-form guide, browse additional examples, or hop into adjacent calculators within the same topic — each one is a quick way to double-check your work or handle a related question without starting from scratch.
Deep dive & study plan
Voltage Divider Calculator: Computes output voltage for resistor dividers with load awareness. It's built around voltage divider, resistors, voltage, so you can go from a raw question to a checked answer without switching tools.
The math behind it: If a load is attached, the effective lower resistance becomes (R₂ × R_load) ÷ (R₂ + R_load), which the calculator applies automatically. The core relationship is Vout = Vin × (R₂ / (R₁ + R₂)), shown above the calculator so you can see exactly how your inputs turn into the result.
To use it well: (1) Enter the supply voltage and resistor values. (2) Add an optional load resistance to see how it drags down the divider output. (3) Review the output voltage, current through the chain, and power for each resistor. Keep your units consistent as you go, and re-run a case you already know the answer to — it's the fastest way to catch a typo before it throws off a result you're relying on.
Worked example: entering Vin = 12 V, R1 = 4.7 kΩ, R2 = 2.2 kΩ, Load = 10 kΩ returns Vout ≈ 3.08 V, Chain current ≈ 1.76 mA. Try swapping in your own numbers next, especially a case you're unsure about, before you use this for something that matters.
Quick retention checklist
- Speak the formula aloud (or annotate it) so the relationships stick.
- Write each step in your own words and compare with the numbered list above.
- Swap in new numbers for the Example to make sure the calculator (and your logic) handles edge cases.
- Check at least one related calculator below — it's the fastest way to confirm your numbers still line up from a different angle.
FAQ & notes
How do I pick resistor ratios?
Use the target Vout to back into resistor ratios, then round to the nearest standard E-series values when selecting parts.
Does it support potentiometers?
Treat the pot as R1 + R2 segments. Adjust each segment to model different wiper positions.
What formula does the Voltage Divider Calculator use?
If a load is attached, the effective lower resistance becomes (R₂ × R_load) ÷ (R₂ + R_load), which the calculator applies automatically.
How do I use the Voltage Divider Calculator?
Enter the supply voltage and resistor values. Add an optional load resistance to see how it drags down the divider output. Review the output voltage, current through the chain, and power for each resistor.