METHOD & GUIDANCE
How this calculation works
Enter figures from the same period and on a consistent VAT-inclusive or VAT-exclusive basis. Tool IQ recalculates every output immediately; nothing you enter is saved or sent to us.
How to use the result
Set the reorder trigger from observed demand and supplier lead time, then review safety stock when demand variability or supplier reliability changes.
Worked example
Demand of 25 units a day over a 12-day lead time uses 300 units; adding 100 safety units produces a 400-unit reorder point.
Common mistakes
- Using peak demand as the average without adjusting safety stock.
- Ignoring supplier processing or transport days.
- Treating stock already on order as unavailable.
Frequently asked questions
Is this calculator free?
Yes. It requires no account and stores no calculation inputs.
Can I use the answer for a formal filing?
No. It is a planning estimate, not accounting, tax, legal or investment advice. Confirm material decisions with a qualified professional.
Should I include VAT?
Use a consistent basis throughout. Businesses that recover input tax commonly model net figures; consumer-facing prices are often considered gross.
Continue the decision
- Inventory Turnover Calculator — Measure how quickly stock turns into sales.
- Cash Runway Calculator — Estimate how many months your available cash will last.
Method reviewed 26 July 2026. Figures are illustrative and calculated locally in your browser.