Timer Prescaler Calculator
Forward: clock + prescaler + period → frequency. Reverse: target frequency → best register pair.
How timer scaling works
Most MCU timers (STM32-style) chain a 16-bit prescaler and a 16-bit auto-reload register:
The prescaler sets the tick duration; the period register counts ticks. For a target frequency this tool searches all valid 16-bit pairs and returns the one with the lowest error — preferring the largest ARR, which also maximizes PWM duty resolution. Both registers hold value − 1: a 72 MHz clock with PSC = 71 ticks at 1 MHz, and ARR = 999 then overflows at exactly 1 kHz.