Guide · 9 minutes read

Inventory planning for a small brand: a forecast checklist for 20 SKUs or fewer

Most inventory forecasting advice is written for companies that have a demand planner, an ERP, and a warehouse team. You have a spreadsheet, a co-packer, and a to-do list with forty other things on it.

Here is the good news. If you sell 20 SKUs or fewer, you do not need any of that. A small range is not a handicap, it is an advantage. You can look at every single SKU by hand, understand it, and plan it well. Big brands cannot. They have to trust the model. You get to use judgment.

This is a practical inventory planning checklist for small brands. You can run it in an afternoon and repeat it monthly. I will give you the four numbers you need, the formulas that matter, and a few mistakes that cost real money. I know the mistakes because I made them at my own brand, and one of them is still sitting in a warehouse racing its best-before date.

First, the mistake that pays for this whole article

At Chilli Chan’s, my food brand, we bought close to two years of stock of one product ahead of a big retail launch. The forecast was built on the launch estimate, not on what we were actually selling. The launch came in far smaller than planned. That stock is now sitting in a warehouse, and we are working hard to move it before it expires.

Nothing about that mistake required a fancy tool to avoid. It required one habit: forecast on demand you can see, not on demand you are hoping for. Every item in the checklist below exists to protect you from a version of that mistake.

Before you forecast: get four numbers per SKU

You cannot forecast anything until you have four numbers for each product. Get these first. Everything else is arithmetic.

Table 1. The four numbers you need per SKU
NumberWhat it isWhere to find itWhat trips people up
Sales velocityUnits sold per day or per week, split by channelShopify analytics, your wholesale orders, retail sell-throughBlending channels into one average hides the truth
Lead timeDays from placing the order to stock you can actually sellSupplier date plus freight plus inbound and QCForgetting freight and the time it sits before it is sellable
On-hand plus on-orderStock you hold now, plus stock already in transitYour inventory sheet and open purchase ordersCounting in-transit stock twice, so you think you have more than you do
Shelf life or obsolescence riskBest-before date, or how fast the product goes out of styleProduct spec sheet, or your own judgment on trendsLeaving it out until it becomes a clearance problem

That last watch-out on the in-transit count is not hypothetical. We once counted an incoming container as on-hand while it was still on the water. It made a month look far healthier than it was. In-transit stock is on-order, not on-hand. Keep the two columns separate.

The checklist

Work through this in order, SKU by SKU. It looks long written out. In practice, once you have done it once, each monthly pass takes minutes per product.

  1. 1
    Rank your SKUs by the money they make

    Even with 20 SKUs, three or four of them almost certainly earn most of your profit. Sort your list by margin contribution, not by units sold. A cheap high-volume line can earn you less than a slow premium one. Spend your forecasting attention where the money is, and keep the long tail simple.

  2. 2
    Match the forecast method to the SKU

    Different demand patterns need different maths, and the right one is usually simple. The table below maps each pattern to the method that fits it.

    Table 2. Which forecast method to use, by SKU type
    Demand patternExample from our rangeMethod to useWhy it fits
    Steady sellerCrispy chilli oil, our hero8 to 12 week moving averageDemand is stable, so a plain average is honest and hard to game
    Trending upA new flavour gaining momentumWeighted moving average, recent weeks count moreCatches growth a flat average would lag behind
    SeasonalHot honey around the Q4 gifting seasonSame period last year, adjusted for growthThe spike is predictable if you look at last year, not last month
    Brand new, no historyA newly launched SKUUse a similar existing SKU as a proxy, forecast low, review weeklyYou have no data yet, so stay humble and correct fast
    Long lead-time importOur knife-cut noodles from TaiwanForecast further out, order to demand, never to fill a containerThe lead time forces you to commit months ahead, so accuracy matters most here
  3. 3
    Work out demand over the lead time

    This is the number that decides when you reorder. It is simply how much you expect to sell while you wait for the new stock to arrive.

    Lead-time demand = average daily sales x lead time in days

    If you sell 12 units a day and your lead time is 21 days, you will sell about 252 units before a new order lands. That is the minimum you need on hand at the moment you reorder.

  4. 4
    Set safety stock on purpose, not by feel

    Most small brands set safety stock by feel, which means too much on some SKUs and too little on the ones that matter. A simple, honest method:

    Safety stock = average daily sales x buffer days

    You choose the buffer days by how risky the SKU is. If you want to be more precise, use the peak-versus-average method:

    Safety stock = (peak daily sales x longest lead time) - (average daily sales x average lead time)

    This sizes the buffer to your actual variability. A steady local product needs a small buffer. A long lead-time import from another continent, paid in a foreign currency, needs a bigger one, because both the demand and the delivery date can move.

  5. 5
    Set the reorder point

    Now combine the two. The reorder point is the on-hand level that should trigger a new order.

    Reorder point = lead-time demand + safety stock

    Table 3. Reorder points for three very different SKUs (illustrative numbers)
    SKUAvg daily salesLead timeLead-time demandSafety bufferReorder point
    Chilli oil (local co-packer)1221 days25210 days = 120372
    Knife-cut noodles (imported, sea freight)875 days60021 days = 168768
    Hot honey (steady, plus a Q4 spike)530 days15014 days = 70220 baseline

    Look at the noodles row. Same small brand, same size of business, but the reorder point is more than double the chilli oil because the lead time is more than triple. This is the single most important thing long lead-time products teach you: you are committing to a demand forecast for three months from now, not next week. Get that one wrong and you get the warehouse problem I described at the top.

  6. 6
    Decide the order quantity against three limits

    The reorder point tells you when. The order quantity tells you how much. Aim to order enough to cover demand until your next planned order, then check it against three real-world limits: your supplier minimum order quantity, your cash, and your shelf life. The right order is the demand-based number, adjusted only as far as those limits force you.

    This is where discipline pays. A supplier offering a discount for a bigger order is not offering you a deal if the extra units expire on your shelf. A minimum order quantity that gives you two years of cover on a product with an 18 month shelf life is not a minimum, it is a write-off with a delay.

  7. 7
    Forecast per channel, then add them up

    DTC, wholesale, and retail do not behave the same way. DTC is steady and driven by your marketing. Wholesale comes in lumps whenever a stockist reorders. Retail depends on rotation, which is how fast each store sells through per week. A blended average hides all of this.

    Forecast each channel on its own terms, then sum them for the total you need to buy. When a retail buyer gives you an opening order, treat it as a one-off event in its own row, not as a new baseline. Ours felt like a new baseline. It was not.

  8. 8
    Plan launches and promotions separately

    A launch order, a promo, or a seasonal gift push is a spike, not your normal demand. If you bake a spike into your baseline forecast, you will over-order for months afterward. Keep one-off events in a separate line, order for them specifically, and go back to your baseline once they are done.

  9. 9
    Run the cash and expiry gate before you commit

    This is the step that would have saved us. Before you send any purchase order, run it past three questions.

    Table 4. The pre-order gate
    CheckThe question to askStop or shrink the order if
    CashCan we pay the deposit and the balance without starving marketing and payroll?The order ties up cash you need to actually sell the stock
    CoverageHow many months of cover does this create at current velocity?It is far beyond your normal reorder cycle for no clear reason
    ExpiryWill this sell through before its best-before date at realistic velocity?Projected sell-through is lower than the stock you are about to hold

    If an order fails any of these, you do not need a better spreadsheet. You need a smaller order.

  10. 10
    Set a review cadence and keep it

    Forecasting is not a once-a-quarter event. Give it a light weekly glance to catch anything moving fast, and a proper monthly reforecast where you update velocities and reorder points. Ten SKUs, twenty minutes. The brands that get burned are not the ones with the wrong model. They are the ones who set a forecast in January and never looked again.

The mistakes that actually hurt small brands

Most inventory advice warns you about stockouts. Stockouts sting, but for a small brand the more dangerous mistake is the opposite one, because it is quiet and it locks up your cash.

Table 5. The five expensive small-brand forecasting mistakes
MistakeWhat it looks likeThe fix
Forecasting on hopeOrdering to a launch or pitch estimate instead of real salesOrder to demand you can already see, treat the launch as upside
Ordering to the discountBuying more to unlock a lower unit priceOnly if it clears the cash and expiry gate
One method for all SKUsSame buffer and cycle for a local product and an overseas importMatch method and buffer to lead time and variability
Ignoring shelf lifeStock expiry is a surprise, not a planPut shelf life in the gate before every order
Forecasting the total, not the channelsOne blended average across DTC, wholesale, retailForecast each channel, then sum

If you avoid only one of these, make it the first one. It is the most tempting, it feels like ambition, and it is the one that put two years of stock in our warehouse.

Where the spreadsheet starts to break

Everything above works fine in a spreadsheet when you have five SKUs and one channel. It gets genuinely painful at fifteen or twenty SKUs across DTC, wholesale, and retail, each with different lead times and different seasonality. The maths does not get harder. The upkeep does. You end up rebuilding the same reorder-point calculations every month and hoping you did not fat-finger a cell.

That gap is why I built OrderBee. It connects to your Shopify data, tracks velocity per SKU, and calculates reorder points and timing for you, so the monthly reforecast is a review instead of a rebuild. To be clear about what it is and is not: OrderBee is forecasting and reorder timing for small Shopify brands. It is not a warehouse system, it is not full inventory management, and it does not do your bookkeeping. It does one job, which is telling you when and how much to reorder, and it tries to do that job honestly.

You do not need it to use this checklist. The checklist stands on its own. But if you are doing this by hand every month and it is eating your evenings, that is exactly the point where a tool earns its keep.

Connect your Shopify storeFrom €49/month, first plan the same day.

The checklist, in one place

Copy this and run it monthly.

  • Pull the four numbers per SKU: velocity by channel, lead time, on-hand plus on-order, shelf life
  • Rank SKUs by margin contribution and focus on the top few
  • Pick a forecast method that matches each SKU's demand pattern
  • Calculate lead-time demand: average daily sales x lead time
  • Set safety stock on purpose, sized to variability and supplier reliability
  • Set the reorder point: lead-time demand plus safety stock
  • Decide order quantity to demand, then check against MOQ, cash, and shelf life
  • Forecast each channel separately, then sum
  • Keep launches and promos in their own line, not the baseline
  • Run the cash and expiry gate before every purchase order
  • Review weekly at a glance, reforecast properly once a month

Frequently asked questions

Use a similar existing SKU as a proxy, forecast conservatively, and review weekly. A new product has no data, so your first job is to gather it fast and correct quickly, not to guess precisely on day one.

There is no single number. The reorder point is lead-time demand (average daily sales times lead time) plus a safety buffer sized to how variable your sales and supplier are. A local product needs a small buffer. A long lead-time import needs a larger one.

Enough to cover normal variation without tying up cash you need elsewhere. Start with a buffer of a set number of days of average sales, larger for risky or long lead-time SKUs. If you want precision, use peak daily sales times longest lead time, minus average daily sales times average lead time.

Per channel, then add them up. DTC, wholesale, and retail behave differently, and a blended average hides the pattern you actually need to plan around.

No. A spreadsheet and this checklist are enough at a small range. Software earns its place when the monthly upkeep across many SKUs and channels starts costing you more time than the planning itself.

Written by Seb Hoffmann, founder of OrderBee. OrderBee is a forecasting tool for small Shopify brands that shows you when to reorder, so you stop guessing and stop tying cash up in stock you cannot sell in time.