Pull-up Resistor Calculator
Find the ideal pull-up or pull-down resistor for I2C buses, open-drain GPIO lines, and switch inputs. Balances rise time against power consumption for your supply voltage and bus speed.
Pull-Up Resistor Design
Pull-up resistors bias a digital line to logic high when a switch/open-drain output isn't actively driving it low. For I2C buses, the resistor value also controls the rise time — too high and the bus becomes slow; too low and current draw increases. For GPIO buttons, a typical 10 kΩ pull-up is fine. Use quick presets for I2C standard speeds, or enter custom values.
I2C standard = 1000 ns · fast = 300 ns · fast+ = 120 ns
PCB trace + device pins — typically 50–400 pF
Recommended Pull-up
3.30 kΩ
- Minimum allowed
- 11.80 kΩ
- Maximum allowed
- 967 Ω
- Geometric ideal
- 3.38 kΩ
- Static current
- 1.00 mA
Nearest standard value is outside the valid range. Adjust rise time or capacitance.
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