Safety Stock Calculator
Buffer stock and reorder point.
Reviewed by James Whitfield · How we check our maths
Your values
ⓘ Live results
Results
- Safety stock
- 139
- Reorder point
- 1,219
- Lead time demand
- 1,080
- Days of cover
- 1.2
Quick answer
Safety stock buffers demand and lead-time variability to hit your target service level.
The formula
Safety stock = Z × SD × √lead time
Worked example
Worked example
Using the values the calculator loads with.
Inputs
- Average daily demand120
- Demand std deviation28
- Lead time9 days
- Service level95%
Result
- Safety stock139
- Reorder point1,219
- Lead time demand1,080
- Days of cover1.2
How to use the Safety Stock Calculator
- 1Enter average daily demand and its standard deviation.
- 2Enter supplier lead time.
- 3Choose the service level you need.
Frequently asked questions
Why not just hold more stock?
Every extra unit ties up cash and risks obsolescence.
What service level should I use?
95% for most items, 99% for critical lines.
About this calculator
- Built and reviewed by James Whitfield · How we build and test calculators
- Report an error