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Inventory Cashflow Planner
Forecast how sales, business costs and new stock purchases could affect the cash available in your reselling business.
See the difference between cash leaving the bank and money remaining invested in inventory.
Reseller Inventory Cashflow Planner
Forecast closing cash, inventory value and reinvestment headroom for a planning period.
Start with the cash and inventory available at the beginning of the planning period.
Enter the sales and stock-cost figures you expect during the planning period.
Add the money you plan to reinvest or take out during the period.
Plan Your Cash Position
Enter your current cash, expected sales and planned spending to forecast your closing position.
Your projected cash at the end of the planning period will appear here.
Cash Buffer Analysis
Projected Business Capital
This combines projected closing cash with inventory valued at the purchase cost entered in your forecast.
How Much Cash Will Your Reselling Business Have Left?
The Inventory Cashflow Planner estimates how much business cash could remain after expected sales receipts, selling costs, overheads, new stock purchases and other cash outflows.
It also tracks inventory separately so you can see when money has moved from cash into stock rather than treating every stock purchase as an immediate business loss.
How the Inventory Cashflow Planner Works
The cashflow side of the calculator starts with the money currently available to the business and then adds or subtracts the cash movements you expect during the planning period.
Projected closing cash
Starting cash
+ expected sales receipts
− selling and fulfilment costs
− business overheads
− stock purchases
− drawings and other outflows
The result is an estimate of the cash that could remain at the end of the period you are planning.
Monthly Reseller Cashflow Forecast
Starting business cash: £1,500
Expected sales receipts: £2,400
Selling and fulfilment costs: £400
Business overheads: £250
Planned stock purchases: £1,200
Drawings and other cash outflows: £300
Calculation: £1,500 + £2,400 − £400 − £250 − £1,200 − £300 = £1,750
Projected closing cash: £1,750
Cashflow Is Not the Same as Profit
This is one of the most important ideas behind the calculator.
Buying £1,000 of resale stock reduces the cash sitting in your business bank account, but the business has not necessarily lost £1,000. You have exchanged cash for inventory.
💷 Cashflow
Tracks money moving into and out of the business.
Buying stock therefore reduces available cash immediately.
📊 Profit
Measures the economic result from the sales and costs included in the calculation.
Unsold inventory remains an asset of the business rather than being treated as stock already sold.
What Does Operating Profit Mean in This Calculator?
The calculator provides a simplified operating profit estimate for the planning period.
Sales receipts
− cost of stock sold
− selling and fulfilment costs
− business overheads
= operating profit
Planned purchases of new inventory are not deducted again from this profit calculation because they are tracked separately as inventory.
Drawings are also excluded from operating profit. Taking money out of the business reduces cash, but it does not make the underlying sales activity less profitable.
How Projected Inventory Is Calculated
Inventory is tracked at the cost you paid for the stock, not its potential resale value.
Projected inventory at cost
Opening inventory
+ planned stock purchases
− cost of stock expected to sell
Opening inventory: £2,000
New stock purchases: £1,200
Cost of inventory expected to sell: £1,000
Projected closing inventory: £2,200
Why Set a Minimum Cash Buffer?
The minimum cash buffer is optional. It lets you specify an amount of business cash that you personally want to keep available rather than continuously reinvesting everything into stock.
For example, if projected closing cash is £1,750 and your chosen minimum buffer is £750:
£1,750 closing cash − £750 buffer = £1,000 above buffer
That does not mean you should automatically spend the entire £1,000. It simply shows how much projected cash sits above the reserve level you entered.
What Is Extra Reinvestment Capacity?
When a minimum cash buffer is entered, SellerStack shows the amount of projected closing cash above that buffer as Extra Reinvestment Capacity.
Treat Reinvestment Capacity as Headroom, Not a Spending Target
The number tells you what could theoretically be available above the cash reserve you selected.
Before reinvesting it, consider upcoming bills, tax reserves, refunds, seasonal sales changes and whether existing inventory is already moving slowly.
What Does Projected Business Capital Show?
The calculator also combines projected closing cash with projected inventory at cost.
Closing cash + closing inventory at cost
= projected tracked business capital
Using the worked example:
Projected closing cash: £1,750
Projected inventory: £2,200
Projected tracked business capital: £3,950
Opening cash plus opening inventory was £3,500, so the example finishes £450 higher.
That £450 also reconciles with the £750 operating profit less £300 taken out of the business.
Keep Every Figure on the Same Planning Period
The Planning Period selector does not automatically multiply, divide or annualise your figures.
It simply identifies the period that your assumptions represent.
- For a one-week forecast, enter one week’s expected figures.
- For a monthly forecast, use expected figures for that month.
- For a three-month forecast, use expected figures covering the full three months.
- Do not combine annual overheads with monthly sales unless you intentionally convert the figures first.
Why Timing Still Matters
This planner estimates the position at the end of a period. It does not know the exact day each sale is paid or when each bill, stock order or withdrawal occurs.
Imagine a monthly forecast showing £1,000 of closing cash. That does not guarantee £1,000 is available in the middle of the month. You might need to pay £800 for stock before £1,500 of customer receipts arrive.
How Resellers Can Use the Cashflow Planner
📦 Before Buying More Stock
Test how a planned inventory purchase could affect the amount of cash left in the business.
💷 Before Taking Money Out
Model drawings or other cash outflows before committing money that may be needed for stock or operating costs.
📈 When Sales Are Growing
Check whether increasing sales is also producing enough cash to fund the inventory needed for continued growth.
🔄 When Cash Feels Tight
Separate money tied up in inventory from the cash actually available to operate the business.
Cashflow and Stock Turnover Work Together
Buying more inventory is not automatically a problem. The problem comes when too much cash moves into stock that then takes a long time to sell.
That is why cashflow should be viewed alongside inventory turnover.
📊 Stock Turnover Calculator
Measure how quickly inventory is moving through your reselling business.
📦 Dead Stock Calculator
Assess ageing inventory and identify stock that may be trapping cash for too long.
Continue Analysing the Business
⏱️ Reseller Hourly Earnings Calculator
Compare your profit with the time spent sourcing, listing, packing and managing sales.
💰 Reseller Profit Calculator
Calculate the profit remaining after the stock, fulfilment and selling costs you enter.
📈 Reseller ROI Calculator
Measure how efficiently the money invested in stock generates profit.
🧰 All SellerStack Tools
Explore the full collection of sourcing, pricing, marketplace, shipping and business tools.
Inventory Cashflow Planning Mistakes to Avoid
- Treating stock purchases as an immediate loss. Buying inventory reduces cash but increases stock held by the business.
- Valuing inventory at hoped-for selling prices. Use inventory cost for this planner.
- Mixing planning periods. Monthly sales should be compared with monthly costs and planned purchases.
- Ignoring the timing of payments. A healthy month-end position does not guarantee enough cash is available earlier in the month.
- Reinvesting every available pound. Keep enough cash for business costs, refunds, tax reserves and unexpected expenses.
- Ignoring slow stock. Inventory may have value at cost while still creating cashflow pressure if it takes too long to sell.
- Treating the forecast as guaranteed. Sales and costs can be different from the assumptions entered.
Profit Matters, but Cash Keeps the Business Moving
A reseller can show profitable sales while still having too little available cash because money is tied up in inventory. Looking at both cash and stock makes that problem much easier to see.
Use this planner before significant stock purchases, during periods of growth and whenever the business feels cash-tight despite appearing profitable.
Inventory Cashflow Planner Methodology
The SellerStack Inventory Cashflow Planner forecasts closing cash using the starting cash, expected sales receipts and cash outflows entered by the user.
Inventory is tracked separately at cost using opening inventory, planned purchases and the cost of stock expected to sell.
The operating profit figure is a simplified planning measure based on sales receipts less cost of stock sold, selling and fulfilment costs, and business overheads.
The calculator does not model exact transaction dates, accounts receivable, accounts payable, tax liabilities, borrowing, depreciation, VAT accounting or other balance-sheet items unless their cash effect is manually reflected in the figures entered.
This calculator is intended for planning and educational use and should not be treated as accounting, tax or financial advice.
Last reviewed: October 2026
Frequently Asked Questions
What is inventory cashflow?
Inventory cashflow looks at how buying and selling stock affects the cash available in the business. Buying inventory reduces cash while selling inventory can return cash to the business.
Is buying stock a business loss?
Not automatically. Buying stock reduces available cash, but the business receives inventory in return. The cost becomes part of the profit calculation when the relevant stock is sold.
What inventory value should I enter?
Use inventory at purchase cost rather than the amount you hope to receive when the stock eventually sells.
What is a cash buffer?
A cash buffer is an amount of business cash you choose to keep available rather than planning to spend or reinvest. The appropriate amount depends on your own business and circumstances.
What does extra reinvestment capacity mean?
When you enter a cash buffer, the calculator shows how much projected closing cash would remain above that amount. It is planning headroom rather than a recommendation to spend the money.
Does the planning period change the calculation?
No. The period selector identifies what period your figures represent. It does not automatically multiply, divide or annualise the numbers you enter.
Why can a profitable reseller still have cashflow problems?
Profit can be tied up in inventory. A seller may generate profitable sales but continually spend cash on replacement or additional stock faster than existing inventory returns money to the business.
Is the Inventory Cashflow Planner free?
Yes. The SellerStack Inventory Cashflow Planner is free to use and does not require a SellerStack account.