A small business budget turns a sales assumption into spending limits and a comparison with actual results. This example is a fictional service-and-product shop with a monthly plan in USD. It is a management illustration; accounting statements and tax records use their own rules.
Build a simple monthly budget
Assume 100 orders at an $80 average selling price, for $8,000 planned sales. Variable product, shipping and payment costs average $28 per order, or $2,800. Fixed costs are $1,200 rent, $600 software and utilities, $600 marketing and $400 insurance, totaling $2,800. The remaining $2,400 is before owner pay, tax and financing costs. If the owner plans a $1,600 draw, only $800 remains as an illustrative cushion. A draw is not necessarily an expense in the formal profit statement.
| Line | Budget | Actual | Difference |
|---|---|---|---|
| Sales | $8,000 | $7,200 | −$800 |
| Variable costs | $2,800 | $2,700 | −$100 |
| Fixed costs | $2,800 | $2,900 | +$100 |
| Before owner pay, tax and financing | $2,400 | $1,600 | −$800 |
The sales shortfall does not by itself explain the whole result. If 90 actual orders generated $7,200, average price stayed $80. Variable cost per order increased to $30 ($2,700 ÷ 90), while fixed costs rose $100. That gives two specific questions: why did order count fall by 10, and why did unit cost rise by $2?
Check cash separately
A separate fictional boutique launch might have a $3,500 merchandise cash ceiling. A $2,640 opening order plus $180 freight uses $2,820, leaving $680 for another buy or a cost overrun. See the opening-stock example for the size mix and buying steps. This launch purchase is independent of the monthly shop budget above; do not add the two scenarios together.
Suppose $800 of those sales will be collected next month while all $5,600 of actual costs are paid now. Cash from these activities is $6,400 − $5,600 = $800 before the $1,600 owner draw, creating an $800 cash gap. The $1,600 operating result is not available cash. Use a dated forecast to see whether opening cash can cover the gap.
The Business Runway & Burn Rate planner can help frame cash scenarios. The monthly cash runway example tests how recurring burn, a reserve and a proposed hire change the cash horizon, while the 13-week cash forecast example shows payment timing in detail. The IRS recordkeeping guidance covers the need to retain supporting income and expense evidence.
Make the next month’s decision
Do not simply raise the next sales target to erase the variance. Check traffic, inquiries, conversion, refunds and stock availability; confirm whether the $2 unit-cost change is a one-off fee or a new supplier price. Then revise the unit assumptions and spending ceiling, and date the revised budget so the original forecast remains auditable.
Make the variance actionable
At 90 orders and $80 per order, actual sales of $7,200 are internally consistent. The $100 decrease in total variable costs compared with budget looks favorable at first, but cost per order rose from $28 to $30. The lower total cost is largely a result of fewer orders. Separate a volume effect from a unit-cost effect before praising the cost control.
The owner can calculate the expected variable cost at actual volume as 90 × $28 = $2,520. Actual variable cost of $2,700 exceeds that by $180. That is the unit-cost variance to investigate. Check supplier invoices, shipping zones and payment fees. The fixed-cost $100 excess may be an unplanned repair or an ongoing price change; classify it before carrying it into next month.
Set a budget review rhythm
At month-end, lock the actual period and retain the original budget. On the first working day of the next month, compare order count, average price, variable cost per order and fixed cost by category. Write one action with an owner and due date for each material difference. A budget is a forecast of choices, so a changed assumption should appear as a new dated version rather than silently overwriting the old plan. Use the bank and accounting records as the source of actuals.
Build the budget from a sales assumption to a controlled review
Step 1 — Set the period and activity driver
The fictional shop budgets one calendar month, with 100 paid orders at an $80 average price. That is $8,000 of planned sales before refunds. The owner records the source of the 100-order assumption, such as recent order history and available stock, rather than inserting a growth target without capacity. If product and service lines have different margins, budget them separately instead of treating every order as identical.
Step 2 — Separate unit costs, fixed bills and owner cash needs
Variable product, shipping and payment costs are assumed to average $28 per order: 100 × $28 = $2,800. Fixed costs are $1,200 rent, $600 software/utilities, $600 marketing and $400 insurance, totaling $2,800. Planned operating remainder is $8,000 − $2,800 − $2,800 = $2,400 before tax, financing and owner pay. The owner proposes a $1,600 withdrawal and retains an $800 illustrative cushion. Because an owner draw may not be an income-statement expense, the formal accounting treatment must be determined separately.
Step 3 — Calculate a threshold and check timing
Each budgeted order contributes $80 − $28 = $52 before fixed costs. Covering the $2,800 fixed budget takes 54 orders when rounded up ($2,800 ÷ $52 = 53.85). If the owner also wants a $1,600 cash withdrawal, a simplified activity threshold becomes 85 orders: ($2,800 + $1,600) ÷ $52 = 84.62. Neither threshold includes tax, debt service, refunds or one-time purchases. Payment dates matter: if $800 of the $7,200 actual sales is collected next month, current-month cash receipts are only $6,400 under the illustration.
Step 4 — Assign spending controls
| Category | Budget owner and action | Trigger to review |
|---|---|---|
| Variable cost | Owner checks supplier price and shipping per order weekly | Above $28 planned per order |
| Marketing | Owner approves campaigns against the $600 ceiling | Spend exceeds plan or retained orders disappoint |
| Fixed bills | Bookkeeper checks due dates and actual invoices | New recurring commitment or $100 variance |
| Owner withdrawal | Owner checks dated cash forecast before transfer | Available cash falls below upcoming obligations |
Step 5 — Close the month, explain variance, and reforecast
Actual sales of $7,200 reflect 90 orders at $80. Variable costs of $2,700 are $30 per order, not the budgeted $28. At 90 orders, expected variable costs would have been $2,520; the $180 excess is a unit-cost issue. Fixed costs are $2,900, another $100 over plan. The resulting $1,600 operating remainder is $800 below the $2,400 budget. Identify whether fewer orders came from traffic, conversion, stock availability or refunds, and whether the $2 cost increase came from suppliers, shipping or payment fees.
The next-month downside case is 80 orders at $80 with $30 unit costs and $2,900 fixed costs: $6,400 − $2,400 − $2,900 = $1,100 before owner pay and tax. That is $500 short of the proposed $1,600 withdrawal even before timing differences. The decision is to revise the cash withdrawal or underlying sales/cost plan, with a dated owner and evidence source. Retain the original budget and the actuals; do not overwrite the forecast to make it look accurate.
Use a versioned budget worksheet
Give the sheet columns for original budget, actual, variance, driver and action. Under sales, record both order count and average price. Under variable cost, record both total and cost per order. Under fixed spending, keep named bills rather than a single “overhead” amount. That lets the owner see that the $100 favorable total variable-cost variance is misleading: there were ten fewer orders, and unit cost actually rose by $2.
Attach a source to each actual: order export for the 90 orders, invoices for the $2,700 variable and $2,900 fixed costs, and bank receipts for cash. If a supplier invoice arrives after month close, record the timing and follow the business’s accounting process; do not silently change a closed actual to make the planning table tidy.
Set the following month’s action with a date. For instance, by day 3 the owner checks the shipping invoices behind the $180 unit-cost difference; by day 5 she reviews lost orders and stockouts; by day 7 she approves a revised order and withdrawal plan that fits the cash forecast. The budget is finished when responsibility and limits are clear, not when the variance table is printed.