How do I calculate optimal stock levels?

Optimal stock = Lead time stock + Safety stock. Lead time stock covers usage during the delivery period. Safety stock provides a buffer for unexpected demand or delivery delays. For a product you use 3 per week with a 5-day lead time and 7-day safety buffer, you need about 4 in stock at all times.

What is safety stock?

Safety stock is the extra inventory kept beyond normal requirements to protect against running out due to unexpected demand spikes, supplier delays, or usage increases. For salons, keeping 7-14 days of safety stock is typical. Popular products and hard-to-get items should have higher safety stock.

How do I track stock levels?

The simplest method is a weekly stock count — check and record quantities of all products. Use a spreadsheet or salon management software. Mark the reorder point on the shelf (when you open the last backup, reorder immediately). Some distributors offer auto-replenishment based on your usage history.

How much money should be tied up in stock?

As a general rule, keep no more than one month worth of product stock. Excessive stock ties up cash, takes up space, and risks products expiring. For a salon spending £500/month on products, aim for £500-£750 in stock value. Fast-moving items can be ordered more frequently in smaller quantities.

CutCalcs

Stock Level Calculator — Optimal Stock Quantities

Calculate optimal stock levels based on usage rates and delivery lead times.

Weekly Usage

How many you use per week

Delivery Lead Time

Days from order to delivery

Safety Buffer

Extra days of stock to keep

Unit Cost

Optional — cost per unit

How We Calculate This

This calculator determines optimal stock levels by combining lead time requirements with safety buffer stock to prevent stock-outs.

The formula

Minimum stock = Daily usage x Lead time (days)

Safety stock = Daily usage x Safety buffer (days)

Optimal stock = Minimum + Safety

Reorder point = Minimum + Half of safety stock

Frequently Asked Questions

Related Calculators

Product Usage Calculator

Track how much product you use per service and estimate monthly consumption.

Reorder Point Calculator

Determine when to reorder products based on usage rate and supplier lead time.

Shelf Life Calculator

Track product expiry dates and calculate remaining shelf life for salon stock.

Product Cost Calculator

Calculate the product cost per individual service for accurate pricing.

Back Bar Calculator

Estimate back bar product consumption and costs for salon services.

Last updated: February 2026

All calculations are estimates. Always perform a strand test before chemical services.