A guitar pedal chain power calculator totals the current draw (mA) of every pedal on your board so you can verify your power supply has enough capacity and headroom. It also checks for voltage mismatches and advises on isolated vs daisy-chain wiring to prevent hum and noise.
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Power Supply
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How to Use the Guitar Pedal Chain Power Calculator
Running out of power supply capacity mid-gig, or dealing with hum from an overloaded daisy chain, are two of the most common pedalboard headaches. This guitar pedal chain power calculator helps you verify your setup before you plug in, so you know exactly how much headroom you have.
Step 1: Add Your Pedals
Use the quick-add buttons for common pedals like Boss pedals (55mA), Strymon units (300mA), TC Electronic pedals (100mA), or a classic Tube Screamer (4mA). For other pedals, enter the name, mA draw (found on the pedal's label or manufacturer website), and voltage requirement. Most standard analog pedals run on 9V DC; some boutique and digital pedals require 12V or 18V.
Step 2: Enter Your Power Supply Rating
Enter the total mA output of your power supply. Budget supplies often provide 500mA on a single daisy-chain output. Quality isolated supplies like the Strymon Zuma or MXR ISO-Brick provide multiple isolated outputs of 100–500mA each. If you have an isolated supply, use the combined capacity of all outputs you plan to use.
Step 3: Read the Results
The pedalboard power calculator shows your total current draw, remaining PSU headroom (percentage), total power in watts, and a visual load bar. If your load exceeds 80%, you will see a warning recommending a higher-capacity supply. If it exceeds 100%, a critical warning appears.
Isolated vs Daisy Chain Advice
If your pedalboard includes any digital pedals (reverbs, delays with presets, modulation with DSP, loopers), the calculator recommends isolated power outputs. Digital pedals inject high-frequency switching noise into the power rail that travels along a daisy chain to your analog pedals, creating hiss, buzz, or interference. Isolated power supplies separate each output electrically, eliminating this issue.
Voltage Requirements
Always match voltage to what each pedal requires. A 9V pedal run at 18V will be damaged immediately. Some pedals designed for 9V can be safely run at 18V for extra headroom — but check the manufacturer's instructions first. The calculator flags any pedals with voltage mismatches against your power supply's setting.
Frequently Asked Questions
Is this guitar pedal power calculator free?
Yes, completely free. No account or signup required. Add your pedals, enter your power supply rating, and get instant results about whether your power supply can handle your pedalboard.
Is my data private when using this tool?
All calculations run entirely in your browser. No data is sent to any server or stored anywhere. Your pedalboard configuration remains completely private on your device.
Why do I need to know my pedal's current draw?
Each pedal draws a certain amount of current (milliamps, or mA) from your power supply. If the total current draw of all your pedals exceeds your power supply's output capacity, pedals may not power on correctly, produce noise, or damage the power supply. Knowing the total helps you choose the right power supply.
What is the difference between isolated and daisy-chain power outputs?
Isolated outputs provide separate, electrically independent power to each pedal, preventing digital noise and ground loop hum from spreading between pedals. Daisy-chain cables share a single power output across multiple pedals — cheaper, but digital pedals on the same chain often inject noise into analog pedals. High-gain or digital pedals should always use isolated outputs.
How much headroom should I leave on my power supply?
Most guitarists recommend leaving at least 20–30% headroom (unused capacity) on the power supply. Running at 90%+ capacity causes voltage sag, which can make pedals behave erratically or produce noise. A power supply with 500mA running 350mA of pedals (70% load) is a healthy setup.
Can I use a 9V power supply for 12V or 18V pedals?
No — always match the voltage to each pedal's requirements. Most Boss and standard analog pedals run on 9V DC. Boutique overdrive and ambient pedals sometimes need 12V or 18V for extra headroom and dynamics. Using the wrong voltage will either damage the pedal or cause it to malfunction. Check each pedal's power requirements before connecting.
What does mA mean for guitar pedals?
mA stands for milliamps, which is the unit of electrical current. It tells you how much current a pedal draws from the power supply. Simple analog pedals like a Tube Screamer draw only 4–10mA, while complex digital pedals or pedals with large displays can draw 200–500mA or more. The total of all mA values must be within your power supply's rated output.
Why do some pedals use more current than others?
Analog pedals with simple circuits (overdrives, fuzzes, compressors) draw very little current — often under 20mA. Digital pedals with DSP processors, reverb algorithms, or MIDI functionality draw much more — sometimes 300–500mA. Pedals with LEDs, backlights, or screens add additional draw. Tube-based pedals draw the most and often require 12V or higher.