Days of Inventory Left Calculator
Check your inventory runway in seconds and spot stockout risk before it disrupts sales.
Input current stock and daily sales
Use this for a quick inventory runway check.
Results
Compare runway days against supplier lead time to avoid reactive restocking.
Days of inventory left
24
Current stock units
1,800
Average daily sales
75
Interpretation
Reorder planning is recommended
Runway is moderate and should be reviewed against supplier lead time.
Worked example
Worked example
Runway check for a live SKU:
How to use
Interpret your result correctly
Use these quick rules to keep pricing and inventory decisions grounded.
- Add current on-hand units.
- Use a realistic average daily sales rate.
- Compare runway vs supplier lead time to avoid stockouts.
Common mistakes
Avoid costly calculation errors
These mistakes usually create hidden margin risk or stock friction.
- Ignoring channel-specific demand spikes.
- Using old sales averages after promotions.
- Treating runway as static while demand changes.
FAQ
Frequently asked questions
Short answers for common edge cases and interpretation questions.
Related
Related tools
Use these next to compare scenarios and validate decisions from multiple angles.
Reorder Point Calculator (Lead Time)
Find when to reorder inventory based on lead time demand and safety stock.
Safety Stock Calculator for E-commerce
Calculate safety stock to protect against demand spikes and lead-time variability.
Upload Inventory CSV for Reorder Alerts
Upload SKU inventory data, map columns, and generate reorder urgency alerts instantly.
Pro
Move from one-off stock checks to ongoing reorder planning
- - Save reorder assumptions
- - Upload bulk inventory CSVs
- - Monitor reorder alerts
- - Export stock planning results