Stack Size Calculator
Estimate the required stack size for an embedded application based on call depth, local variables, and interrupt overhead.
Deepest function call nesting
Return address + saved registers + locals
Recommended Stack Size
480 bytes
Recommended Stack Size vs Max Call Depth
Estimating Stack Size for Embedded Systems
Stack overflow is a common and dangerous bug in embedded systems. Proper sizing prevents crashes.
Formula
Base Stack = Max Call Depth x Avg Frame Size
ISR Stack = Interrupt Levels x ISR Frame Size
Recommended = (Base + ISR) x (1 + Safety Margin)
The safety margin accounts for worst-case alignment, compiler-generated temporaries, and unforeseen call paths. A 25% margin is typical for production systems.
Example Calculation
8-deep call stack, 32-byte frames, 2 interrupt levels at 64 bytes each, 25% safety.
- 01Base stack: 8 x 32 = 256 bytes
- 02ISR stack: 2 x 64 = 128 bytes
- 03Total raw: 256 + 128 = 384 bytes
- 04With 25% margin: 384 x 1.25 = 480 bytes
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