How Much Inventory Should You Really Hold? A Practical Guide for Scaling Consumer Brands

“How much inventory should my business have on hand?”

It’s the question that keeps founders up at night — usually sometime between reconciling cash flow and approving the next PO. And it’s a fair question. Get this wrong, and inventory can quickly drain cash and stall growth.

If only there were a clean, one-size-fits-all answer.

Like most things in inventory planning, the answer is nuanced. The right inventory level is a balance of data, experience, and context — and that balance shifts as your brand grows.

At Boon, we spend our days inside this exact problem with scaling product-based brands. This guide brings together the frameworks we use to help retail brands stop guessing — and start making inventory decisions that actually support growth.

Why Getting Inventory “Right” Matters So Much

At the end of the day, this basically comes back to money.

Inventory is one of the largest uses of cash in a product-based business. (Inventory is likely your top expense!) When it’s balanced, it gives you flexibility. When it’s off, it creates a domino effect across your entire P&L.

We see it all the time:

Too much inventory → cash tied up, high storage costs, increased markdowns, margin erosion, dead stock
Not enough inventory → missed sales, frustrated (or lost) customers, wasted marketing spend

Inventory doesn’t live in isolation. It’s the engine that keeps your brand running. Miss on quantity, timing, or location, and inventory quietly becomes a bottleneck to growth.

The 4 Inputs That Actually Determine How Much Inventory You Should Hold

There’s no universal number for how much inventory you should have on hand — but there is a repeatable way to think about it.

1. Sales Velocity (Your True Demand)

Before you can make confident inventory decisions, you need a clear understanding of how fast product is actually moving. This sounds simple — but for many growing brands, forecasting demand accurately is where things quietly start to break down.

We often see teams grappling with:

Incomplete sales data because of recent stockouts
A few hero SKUs masking underperformance elsewhere
Channel differences that blur what “true demand” really looks like
Reporting that shows totals, but hides SKU-level risk

Looking only at topline sales can mask demand issues — making it harder to see what’s truly selling and what’s simply tying up cash.

That’s why we encourage brands to look beyond totals and focus on:

Average weekly sales by SKU and category
Sell-through rates across core vs. fashion product
Channel-level performance (DTC, wholesale, and third-party marketplaces like Amazon or Faire)
Where stockouts may be suppressing demand signals

This is also where analyzing weeks of supply (WOS) becomes invaluable. Reviewing WOS across categories and subcategories helps surface risk early — before excess inventory or stockouts show up as a financial problem.

The goal isn’t perfect precision. It’s visibility. When you can clearly see what’s driving sales (and what isn’t), inventory decisions stop feeling like guesswork.

A simple starting point: calculate average weekly sales by SKU using only in-stock periods, then compare that to weeks of supply. The gaps will tell you far more about demand than topline revenue ever could.

2. Vendor Lead Times

Lead time is often understood in theory — but underestimated in practice. As brands scale, lead times rarely stay static. Vendors get busier, production schedules tighten or lengthen based on volume, freight timelines shift, and suddenly the assumptions that once worked no longer hold.

We commonly see brands struggling with:

Planning inventory as if replenishment is instant
Using outdated lead time assumptions from earlier growth stages
Carrying safety stock that no longer matches actual demand
Discovering too late that demand has outpaced supply

If you typically hold two weeks of safety stock but your vendor needs four weeks to produce and ship, you’ve already built a stockout into your plan — even if sales are strong.

Understanding lead times allows you to:

Set realistic reorder points
Define true minimum inventory levels
Protect sales during demand spikes or supply chain delays

**A simple starting point:** map each core product’s vendor lead time directly against its weeks of supply. If lead time is longer than your coverage, you’re exposed. If it’s shorter, you may have room to buy less upfront and replenish more intentionally. An Open-to-Buy tool is especially advantageous for mapping lead time against weeks of supply based on anticipated demand.

This is one of the clearest ways to turn lead time from a background detail into an active planning input.

3. Product Mix: Core vs Fashion

Not all inventory carries the same level of risk — but many brands plan it as if it does.

As assortments grow, it becomes harder to separate what’s truly dependable from what’s designed to create excitement. Without that distinction, inventory volatility creeps in quietly.

We often see brands wrestling with:

Too many SKUs competing for the same dollars
Fashion product being bought with core-level confidence
Core product being underfunded to make room for newness
End-of-season regret tied to “everything felt like a priority”

Core inventory — your evergreen, proven sellers — can usually support higher weeks of supply and more aggressive replenishment. Fashion, seasonal, or trend-driven products have shorter lifecycles and need tighter controls.

When these two types are planned the same way, brands tend to experience lower forecast accuracy, more markdowns and less predictable cash flow.

Getting clear on this mix isn’t about limiting creativity. It’s about giving newness the right role — one that drives excitement without putting the business at risk.

A simple starting point: explicitly classify each SKU as core or fashion, then plan weeks of supply differently for each. If you’re holding similar coverage across both, your inventory risk is higher than it needs to be.

4. Cash Flow & Growth Goals

Inventory planning is rarely just an operational exercise — it’s a financial one.

For many founders, this is where decision-making feels most charged. You’re balancing growth ambitions with very real cash constraints, often without a senior inventory leader to sense-check the tradeoffs.

Common challenges we hear:

“We want to grow, but we can’t afford to overbuy.”
“We’re scared of stockouts, but nervous about tying up cash.”
“We don’t want inventory to limit our marketing plans.”

The goal isn’t to carry as little inventory as possible. It’s to carry enough to support sales while leaving the business room to breathe.

For many growing brands, that often looks like around four weeks of supply on hand as a baseline — layered with vendor lead time and safety stock where needed. It’s not a rule, but a practical guardrail.

When inventory decisions are anchored to both cash flow and growth priorities, teams gain clarity — and confidence — even when tradeoffs are required.

A simple starting point: Decide how many weeks of inventory your cash can realistically support before placing the next buy. Use that number as a planning guardrail — then layer in lead time and safety stock to see where growth plans and cash constraints collide.

This reframes inventory from “how much can we buy?” to “how much can the business sustainably carry?”

The Metric We Come Back to Again and Again: Weeks of Supply (WOS)

If there’s one metric founders should feel comfortable with, it’s this:

Weeks of Supply (WOS) = (On Hand + On Order) ÷ Average Weekly Sales

On its own, WOS looks simple. In practice, it’s one of the most useful tools for spotting risk early — before inventory problems show up in your cash flow or customer experience.

We often see brands tracking WOS after the fact, or only at a total business level. That’s where issues start to hide.

Used proactively, WOS helps you:

Spot overstocks early, before markdowns are the only option
Reduce stockouts by flagging low coverage ahead of time
Standardize planning conversations across buying, planning, and finance
See risk forming at the SKU or category level — not just in totals

Typical WOS Benchmarks We See

While there’s no single “right” number, healthy ranges for scaling brands tend to look like:

Core styles: 8–12 weeks
Fashion / seasonal styles: 4–8 weeks
New products: varies based on risk, marketing support, and vendor lead time

When WOS creeps above ~16 weeks, inventory usually starts tying up cash. And it’s worth pausing here — 16 weeks is an entire season. Ask yourself: will the inventory you brought in to support demand in March still feel relevant to customers in July?

On the other end of the spectrum, when WOS drops below ~6 weeks, sales risk increases quickly. For many brands working with overseas manufacturers, inventory often takes at least 4 weeks to arrive at a U.S. port — and that’s before it’s received, processed, and ready to sell.

This is where lead time and WOS need to be viewed together. If your lead time is longer than your coverage, stockouts aren’t a surprise — they’re built into the plan.

The goal isn’t to lock yourself into a perfect WOS number. It’s to use WOS as an early-warning system so inventory decisions stay intentional instead of reactive.

When You Have Too Much Inventory

Extra inventory may not feel like a problem right away.

It shows up as a little more back stock than planned, a style that “just needs more time,” or a color you’re confident will pick up. But excess inventory doesn’t announce itself loudly — it compounds quietly.

Over time, it shows up as:

Higher storage and carrying costs
Missed selling windows
Excess markdowns that erode margin
Obsolete inventory that’s difficult to move (or needs to be liquidated)

In most cases, the issue isn’t total inventory — it’s misallocated inventory.

Why Excess Inventory Builds (Even When Sales Look Fine)

We often see excess inventory driven by a few common planning patterns:

Buying breadth (more SKUs, colors, or variations) without clear demand signals
Planning fashion product with core-level confidence
Relying on topline sales while missing SKU-level underperformance
Avoiding tough assortment decisions because everything feels “important”
Overbuying to protect against stockouts — without distinguishing risk by product type

This is where weeks of supply becomes critical. High WOS doesn’t always mean strong coverage — it often signals slow-moving inventory concentrated in the wrong places.

A Real-World Example

We worked with a seasonal apparel brand that loved offering a wide variety of colors and prints. When we looked at performance at the SKU level, we found certain colors with extremely high WOS due to very little customer demand.

That assortment review — combined with more intentional planning — helped the brand do more sales with less inventory spend. They also benefited from better vendor costing, healthier inventory turns, stronger margins, and far less stress at the end of each season.

This is the power of looking beyond totals and using WOS to help guide decisions at the SKU and category level.

When You Don’t Have Enough Inventory

Running out of inventory is often framed as a “good problem to have.” It means strong demand, right?

In reality, chronic stockouts usually signal a planning issue — not just a demand spike.

At first, being out of stock may feel manageable. Customers sign up for back-in-stock alerts. You promise a restock is coming. But when it happens repeatedly, the costs compound quickly:

Missed sales you can’t get back
Frustrated customers who shop with your competitors instead
Marketing spend that underperforms because traffic can’t convert
Demand data that becomes unreliable because sales are artificially capped

Why Stockouts Happen (Even When Sales Are Strong)

Most stockouts aren’t caused by unexpected demand alone. They’re usually the result of a few planning gaps working together:

Weeks of supply that don’t reflect actual sales velocity
Vendor lead times that are longer than inventory coverage
Reorder points based on outdated assumptions
Over-rotating into newness at the expense of proven core product
Fear of overbuying after a previous season’s excess inventory

A Real-World Example

We often see this with fast-growing brands after a strong launch or campaign. A core product sells through faster than expected, but reorder points are still based on earlier volumes. By the time the team recognizes the shift in demand, vendor lead times make it impossible to restock quickly — turning strong momentum into missed sales and unreliable demand data.

The Hidden Cost of Being Out of Stock

Beyond lost revenue, stockouts undermine future planning.

When inventory runs out:

Sales history stops reflecting true demand
Forecast accuracy declines because data is suppressed
Teams lose confidence in plans
Replenishment decisions become reactive

Over time, this creates a cycle where teams consistently underbuy — not because demand isn’t there, but because visibility is missing.

How to Reduce Stockout Risk Without Overbuying

The solution isn’t simply “buy more inventory.” It’s building protection where it matters most.

We often start by helping brands:

Identify core products that deserve higher minimum inventory levels
Align weeks of supply targets with true vendor lead times
Set clear reorder points based on sales velocity, not intuition
Monitor WOS at the SKU and category level — not just in total
Review inventory weekly so adjustments can be made early

When stockout risk is visible, decisions become calmer and more intentional.

Where to Start: New vs Established Brands

The “right” inventory approach depends heavily on where your brand is in its lifecycle. Newer brands and more established ones face very different planning challenges — and trying to plan like a company you’re not yet can create unnecessary risk.

If You’re Newer

For newer brands, inventory planning often happens with limited data, limited cash, and a lot of pressure.

You may be dealing with:

Little to no sales history
Uncertain customer behavior
Long or inflexible vendor lead times
The need to look “fully merchandised” without overcommitting cash

At this stage, the challenge isn’t optimization — it’s balance.

We usually recommend focusing on:

Inventory spend vs cash flow
Vendor lead times and minimums
A tighter, more manageable assortment

Many newer brands use ~4 weeks of supply as a starting point — not because it’s perfect, but because it creates a guardrail. From there, you layer in lead time and safety stock so you’re not immediately exposed to stockouts.

Precision matters less than staying flexible long enough to learn what demand is really telling you, and respond accordingly.

If You’re More Established

With more data, planning can evolve — but it doesn’t automatically get easier.

Instead of not enough data, the challenge becomes:

Too much data without a clear framework
More SKUs, categories, and channels to manage
Tension between past performance and future growth goals

This is where we often use a Top-Down vs Bottom-Up approach:

Top-down: market size, category trends, growth targets
Bottom-up: SKU-level demand, historical performance, promotion plans

Comparing both — and landing somewhere in the middle — helps brands set goals that are ambitious and achievable.

Your demand and inventory forecasting will never be perfect. But when it’s thoughtful and structured, it becomes a tool for alignment and a roadmap to growth.

The Bottom Line

Inventory planning is both an art and a science.

There’s no forecast that will be 100% accurate — but there is a way to make inventory decisions calmer, clearer, and far less reactive.

When inventory is treated as a strategic asset instead of a guessing game, everything else gets easier.

And if you want help building that structure, the Boon team is always here.

Ready to Make Inventory Decisions Feel Calmer?

If inventory planning feels stressful, you’re not doing anything wrong — you’re just operating without enough structure yet.

At Boon, we partner with growing product-based brands to:

Build realistic demand forecasts
Set clear weeks-of-supply targets
Design open-to-buy plans that protect cash
Reduce stockouts and overstocks
Turn inventory into a strategic growth lever

Whether you’re early-stage and trying to avoid costly mistakes, or more established and ready to bring clarity to a complex assortment, we meet you where you are.

If you want a second set of eyes on your inventory — or help building a plan you can actually trust — we’d love to support you.

→ Book a call with the Boon team

How Much Inventory Should You Really Hold? A Practical Guide for Scaling Consumer Brands

How Much Inventory Should You Really Hold? A Practical Guide for Scaling Consumer Brands

Why Getting Inventory “Right” Matters So Much