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Inventory Investment Calculator

See expected profit, break-even units, and unsold risk before you commit cash to inventory.

Enter every amount in the same currency. This selector only changes the symbol shown — it does not convert exchange rates.

Expected profit

$865.00

High Profit Potential

Total investment

$550.00

Break-even units

46

Expected units sold

75

25 unsold at sell-through

This inventory plan looks profitable at the given sell-through.

Short example

Buying 100 units at $5.00 = $500.00 investment + $50.00 storage. Selling 75 at $20.00 with 10% + $0.30 fees and $0.50 packaging returns ~$500.00 profit; break-even ≈ 45 units.

All calculations are estimates based on average platform fees. Real profits may vary depending on category, ads, and shipping.

Inventory projections are planning estimates only. Actual sell-through, storage costs, and fees vary.

Free worksheet for your next step

Turn this calculator result into a plan with a matching worksheet, checklist, or printable resource.

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    Handmade Inventory Tracker

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How to use this calculator

  1. Enter your numbers in each field above — the calculator updates instantly as you type, so there's nothing to submit.
  2. Use your real figures when you have them, or sensible estimates while you're planning. If a field doesn't apply, leave it at zero.
  3. Compare the results, then change one input at a time to see how each lever (price, cost, fees, volume) moves the outcome.

When to use this calculator

  • Before buying inventory, so you know whether the purchase is worth the cash risk.
  • When a supplier's minimum order is larger than you'd choose.
  • Before committing to a seasonal buy that has a hard sell-by date.
  • When comparing two products and only enough cash for one.

Formula

Investment = Units × Cost + Storage · Expected profit = Units sold × (Price − Cost − Packaging − Fee/unit) − Storage · Break-even units = Investment ÷ (Price − Cost − Packaging − Fee/unit)

Worked example

100 units × $5 = $500, $50 storage, $20 price, 75% sell-through, 10% + $0.30, $0.50 packaging.

  1. Investment = $550
  2. Fee/unit = $2.30
  3. Contribution/unit ≈ $12.20
  4. Break-even ≈ 45 units
  5. Expected profit at 75 sold ≈ $500

Answer: ≈ $500 expected profit, 45 units to break even

How it works

Inventory is the biggest cash risk in most small businesses. Modeling sell-through at 50%, 75%, and 100% before you buy prevents the classic 'sold well but never recovered the outlay' trap.

Expert tips

  • Always model a pessimistic sell-through alongside your expected one — the gap is your real risk.
  • Include storage, and for long-hold stock add a little for the cash being unavailable.
  • Order smaller test quantities on unproven products even when the unit price is worse.
  • Compare break-even units to your realistic monthly sales; if it takes more than a season, rethink the size of the order.

How to interpret your results

  • Dollar values are shown per sale, per order, or per item unless a result is explicitly labelled monthly, weekly, or daily.
  • Percentages (margin, ROI, conversion rate) are easier to compare across products and price points than raw dollars — use them when you benchmark.
  • A positive result means you're ahead after the costs and fees you entered. A negative result means the current numbers don't work — change a lever (raise price, cut a cost, lower ad spend) and recalculate.
  • Treat the output as a planning estimate, not a guarantee. Fees, taxes, and conversion rates shift over time — re-run the numbers whenever a key input changes.

Common mistakes

  • Assuming 100% sell-through — very few products hit it.
  • Ignoring storage and holding cost over time.
  • Buying quantities based on supplier minimums instead of realistic sales.

Related Guides

Go deeper with plain-English guides on the same topic.

FAQ

What sell-through should I plan for?
New products: 50%. Proven products: 75–85%. Anything above 90% suggests you're actually short on inventory.
How is this different from Break-Even Calculator?
Break-Even is generic. This one models units, sell-through, packaging, and fees specifically for inventory decisions.
What numbers do I need?
Units you plan to buy, cost per unit, any storage cost, your sale price, expected sell-through percentage, packaging cost, and your fee percentage.
What does ROI mean here?
It's the profit you expect compared to the cash you put in. A 30% ROI means every $100 spent on stock is expected to return $130 in total.
Why is cash tied up in stock a problem?
Money sitting in boxes can't pay for ads, restocks, or bills. Even a profitable purchase can squeeze you if it sells slowly.
How do I judge slow-moving risk?
Run the numbers at 50% sell-through as well as your hopeful figure. If the low case loses money, the order is too big.

Why trust this calculator?

This tool uses standard mathematical formulas and commonly accepted calculation methods, shown openly in the Formula section above so you can verify the math yourself. Results are estimates based on the information you enter and do not account for every individual circumstance. For important financial, tax, legal, medical, or business decisions, please double-check with a qualified professional before acting on the numbers.

What to calculate next

Use this before buying inventory so you know whether the purchase is worth the cash risk. Next, check how fast similar stock has been moving, what unsold units would cost you, and when the reorder should actually land.

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