Voltage Divider Calculator
Output voltage and current from a resistor voltage divider
Quick Answer — Voltage Divider
The Voltage Divider Calculator is a free online engineering tool that helps you output voltage and current from a resistor voltage divider. Enter your values above for instant, accurate results — no signup required. All calculations run privately in your browser.
Maintained by: Sagar Sahni, Calc Labz | Review: formula checks, worked examples, and periodic updates
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Interactive Diagram
Voltage divider circuit schematic
Step-by-Step Formula Derivation
Mathematical derivation for the Voltage Divider Calculator
Applicable Standards & Codes
Engineering standards referenced by the Voltage Divider Calculator
Engineering Reference
Learn the theory behind the Voltage Divider Calculator
A voltage divider is a simple circuit with two series resistors that produces an output voltage as a fraction of the input voltage. The output voltage Vout = Vin × R2/(R1+R2) is determined by the resistor ratio, not the absolute values. However, the absolute values determine the quiescent current I = Vin/(R1+R2) and the divider's output impedance Zout = R1∥R2.
For the voltage divider to function accurately, the load impedance must be much greater than R2 (rule of thumb: Z_load > 10×R2). Loading effects reduce the output voltage below the calculated value. This is why voltage dividers are generally used only for signal-level applications (sensor biasing, ADC reference), not for power delivery.
Formula & Worked Example
The math behind the Voltage Divider Calculator
Mathematical Formula
Result = F(x_1, x_2, \dots, x_n)Step-by-Step Worked Example
Frequently Asked Questions
Common questions about the Voltage Divider Calculator
What is the Voltage Divider Calculator?
How do I use the Voltage Divider Calculator?
Is my personal data saved when using this calculator?
Can I use the Voltage Divider Calculator on my mobile phone?
How accurate is the Voltage Divider Calculator?
What is the Voltage Divider Calculator?
The Voltage Divider Calculator is a free online engineering tool that helps you output voltage and current from a resistor voltage divider. Built for accuracy and speed, this calculator uses verified formulas and provides instant results without requiring any signup or registration. All calculations run entirely in your browser, ensuring complete privacy — no personal data is ever sent to our servers.
How to Use the Voltage Divider Calculator
- Enter Input Voltage (Vin): Enter your input voltage (vin) (in V) in the input field. The calculator will validate your input automatically.
- Enter R1 (top resistor): Enter your r1 (top resistor) (in Ω) in the input field. The calculator will validate your input automatically.
- Enter R2 (bottom resistor): Enter your r2 (bottom resistor) (in Ω) in the input field. The calculator will validate your input automatically.
- View Your Results: The Voltage Divider Calculator displays your results instantly in the output panel. You will see the primary result along with a detailed breakdown of secondary outputs. Scroll down for charts, interpretations, and expert advice.
Key Features
- Instant Voltage Divider calculations with real-time updates
- No signup, no registration — 100% free forever
- All calculations happen in your browser — zero data sent to servers
- Works offline as a Progressive Web App (PWA)
- Mobile-friendly responsive design
- Verified engineering formulas updated for 2026
Why Use Calc Labz Voltage Divider Calculator?
The Calc Labz Voltage Divider Calculator stands out because it combines accuracy with simplicity. Unlike other online calculators, we provide detailed breakdowns, step-by-step formulas, and actionable advice alongside your results. Our engineering calculators are regularly updated to reflect current rates, rules, and standards for India (2026). Whether you are a student, professional, or just need a quick calculation — Calc Labz delivers reliable results instantly.
Key Terms & Glossary
- Ohm's Law
- V = I × R — Voltage equals Current times Resistance. The fundamental law of electrical circuits.
- Power Factor
- The ratio of real power to apparent power in an AC circuit, ranging from 0 to 1.
- Torque
- A rotational force measured in Newton-meters (N·m) that causes an object to rotate about an axis.
- Reynolds Number
- A dimensionless quantity predicting whether fluid flow is laminar (smooth) or turbulent.