How to Set Minimum Stock Levels (and Actually Follow Them)

Running out of nitrile gloves mid-procedure or discovering that the last tube of a client's signature hair color was used yesterday -- these are the moments that turn a normal workday into a stressful scramble. Minimum stock levels exist to prevent exactly this. Yet most clinics and salons either skip them entirely, set them once and forget about them, or pick numbers based on gut feeling rather than data.

This guide walks you through a practical, formula-based approach to setting minimum stock levels that actually work -- and, just as importantly, how to build the habits that keep them effective over time.

What Are Minimum Stock Levels and Why Do They Matter?

A minimum stock level (also called a reorder point) is the quantity at which you should place a new order for an item. Drop below that number and you risk running out before the next delivery arrives.

For service businesses like dental practices, physiotherapy clinics, beauty salons, and veterinary offices, the consequences of a stockout go beyond inconvenience. You may need to cancel or reschedule appointments, turn to expensive same-day suppliers, substitute with inferior products, or disappoint clients who expect consistency.

At the same time, setting minimums too high means capital is sitting on shelves instead of working for you. A beauty salon that keeps six months of toner in stock is paying for storage space and tying up cash that could go toward marketing or equipment upgrades.

The goal is balance: enough stock to keep operations running smoothly, but not so much that you are overspending.

The Reorder Point Formula Explained Step by Step

The most widely used formula is straightforward:

Minimum Stock Level = (Average Daily Usage x Lead Time in Days) + Safety Stock

Let us break each component down.

Average Daily Usage

This is how much of an item your business consumes on a typical working day. To calculate it, take total usage over a representative period (two to four weeks works well) and divide by the number of working days in that period.

For example, a dental clinic uses 60 boxes of disposable bibs in a 20-day working month. Average daily usage = 60 / 20 = 3 boxes per day.

Lead Time

Lead time is the number of working days between placing an order and receiving it. Include everything: order processing, shipping, and any inspection or put-away time on your end.

If your dental supplier ships within 24 hours and delivery takes two working days, your lead time is three working days. If you order from an overseas supplier with a 10-day transit window, that number is obviously much higher.

Safety Stock

Safety stock is your buffer against variability -- unexpected spikes in demand, late deliveries, or supplier shortages. A common starting point is 20 to 30 percent of your base stock need (average daily usage multiplied by lead time). Increase the percentage for items where a stockout would be critical (anesthetic, sterilization pouches) and decrease it for items where a short delay is manageable (office supplies, marketing materials).

Practical Examples for Clinics and Salons

Example 1: Nitrile Examination Gloves in a Dental Practice

When your inventory hits 50 boxes, it is time to reorder. This gives you enough to keep working through the lead time plus a cushion for a delivery delay or a particularly busy week.

Example 2: Professional Hair Color Tubes in a Salon

Hair color is trickier because you carry many shades, each with different usage rates.

For slower-moving shades used only two or three times per month, the minimum might be as low as two tubes -- but never zero, because a single surprise appointment could require it.

Example 3: Autoclave Sterilization Pouches in a Physiotherapy Clinic

Sterilization supplies are non-negotiable -- without them you cannot treat patients. The safety stock percentage here is lower because the item is easy to source from multiple suppliers in an emergency.

How to Calculate Safety Stock More Precisely

The 20-to-30-percent rule of thumb works for most small businesses, but if you want more precision, consider these factors:

Demand Variability

If your daily usage swings widely (say, 5 boxes one day and 15 the next), you need a larger buffer. Look at the range of your daily usage over the past month. The wider the range, the higher your safety stock should be.

Supplier Reliability

A supplier who consistently delivers in three days needs less buffer than one who sometimes takes three days and sometimes takes seven. Track actual delivery times for your top suppliers and factor the worst-case scenario into your safety stock.

Criticality of the Item

Ask: what happens if we run out? If the answer is "we cancel appointments" or "we face a compliance violation," bump up the safety stock. If the answer is "we use a slightly different brand for a day," you can afford a thinner buffer.

Seasonality and Promotions

A beauty salon running a holiday promotion on facials will use more masks, serums, and cotton pads than a typical month. Adjust minimums ahead of predictable demand spikes, then return to standard levels afterward.

Common Mistakes When Setting Minimum Stock Levels

Setting Levels Once and Never Updating Them

Your business is not static. New services, changing client demographics, supplier switches, and seasonal trends all affect usage. Review your minimum levels at least once per quarter. Compare your calculated minimums against actual consumption and adjust where they have drifted.

Using the Same Buffer for Every Item

A 25 percent safety stock makes sense for standard consumables, but it is overkill for paper towels and insufficient for controlled substances or specialty products. Categorize your items by criticality and adjust buffers accordingly.

Ignoring Lead Time Variability

You might record a supplier's lead time as "3 days" because that is what their website says, but actual deliveries might range from 2 to 6 days. Use the realistic average, not the advertised one, and make sure your safety stock accounts for late arrivals.

Not Accounting for Minimum Order Quantities

Some suppliers require minimum orders. If your reorder point suggests ordering 8 boxes but the supplier minimum is 20, you need to adjust your process. You might set a lower minimum level to accommodate the larger order, or find a supplier with a lower minimum.

Relying on Memory Instead of Alerts

Even the best-calculated minimum level is useless if nobody checks it. Manual systems depend on someone remembering to look -- and on busy days, that does not happen. Automated alerts that notify you when stock drops to the reorder point remove human error from the equation.

How to Make Minimum Levels Part of Your Routine

Automate Notifications

The single most impactful step is setting up automatic low-stock alerts. When your inventory management system sends a notification as soon as a product hits its minimum level, you do not need to remember to check. The system does the watching for you.

Assign Ordering Responsibility

If everyone assumes someone else will place the order, nobody will. Assign a specific person (or a specific role) as the owner of reordering for each category of supplies. That person receives the alerts and acts on them.

Build a Reorder Checklist

When a minimum level alert fires, the responsible person should have a clear process: verify the current count, check if an order is already in progress, confirm the quantity to order, and place the order. A simple checklist prevents duplicate orders and missed steps.

Schedule Quarterly Reviews

Put a recurring calendar event for minimum-level reviews. During the review, pull actual usage data for the past quarter, compare it to your current minimums, and adjust where needed. This takes 30 to 60 minutes per quarter and pays for itself many times over in prevented stockouts and reduced overstock.

Track Your Hit Rate

Keep a simple log of stockouts -- items that reached zero before a new delivery arrived. If you are experiencing more than one or two stockouts per quarter, your minimums need tightening. If you never come close to running out and always have large surpluses when new orders arrive, your minimums might be too conservative.

Minimum Stock Levels for Different Business Types

Medical and Dental Clinics

Focus on compliance-critical items first: PPE, sterilization supplies, medications, and single-use instruments. These items should have higher safety stock percentages (25 to 40 percent) because the cost of a stockout is patient safety and regulatory risk. Non-clinical supplies like printer paper or cleaning products can use standard buffers.

Beauty Salons and Spas

Color products, treatment-specific consumables, and retail inventory each have different dynamics. Color and treatment supplies tie directly to appointments and should be set based on booking forecasts. Retail inventory turns more slowly and may need lower minimums but wider variety.

Veterinary Practices

Similar to medical clinics, but with the added complexity of species-specific supplies. A veterinary practice might stock multiple sizes of endotracheal tubes, each with low individual usage but critical when needed. Set minimums at the individual SKU level, even if the quantity is just two or three.

Take Control of Your Stock Levels with Asseto

Setting minimum stock levels is one of the highest-return improvements you can make in your inventory management. It prevents the stress of stockouts, eliminates expensive emergency orders, and keeps your cash from sitting idle on shelves.

Asseto makes this process simple. Set minimum levels for every consumable, get automatic alerts when stock drops below the threshold, and review usage trends to keep your numbers accurate over time. Whether you manage a single clinic or multiple locations, Asseto gives you the visibility to make smarter reordering decisions without spreadsheets or guesswork.

Start your free trial at asseto.app and set your first minimum stock levels today.