Cost revenue analysis: compare costs, sales and profit

Cost revenue analysis explains how sales, variable costs and fixed operating expenses combine to produce operating profit. Compare matching periods, then build a bridge that separates the reasons profit changed. Higher sales alone do not establish that the business earned more.

Define the profit measure before opening the exports

For an internal operating comparison, use this structure:

Contribution = Net revenue − Variable costs

Operating profit = Contribution − Fixed operating expenses

Profit change = Revenue change − Variable cost change − Fixed expense change

This is a management view of cost behavior. It is different from gross profit margin, which subtracts the accounting cost of goods sold. The IRS's Publication 334 explanation of gross profit also distinguishes net receipts after returns and allowances from cost of goods sold. Use that distinction when cleaning the sales export; do not substitute tax classifications for your company's reporting policy.

Include every operating expense once. Here, fixed operating expenses include all remaining operating costs after variable costs, including depreciation where applicable. Interest, income taxes and nonoperating items sit outside the example. If your ledger classifies costs differently, reconcile its presentation to this management view with a mapping rather than silently dropping expenses.

Prepare matching sales and expense rows

Start with the closed sales register, inventory cost or production cost report, and operating expense ledger. Keep document ID, posting date, product or business unit, quantity, net revenue, cost account and signed expense amount. Preserve credit memos and reversals as separate rows linked to their original documents.

Use recognized sales and the costs matched to those sales. Purchases are not automatically the cost of goods sold: inventory may remain unsold. The cost of goods sold guide covers that reconciliation. For this example, all units in the table were sold and their variable costs were expensed in the same period.

Map accounts to variable and fixed costs with the controller. A production supervisor's salary may be fixed within the period even though it belongs in production costs. A sales commission may vary with revenue even though it is outside production. Mixed accounts need an explicit split or their own disclosed category.

To roll up an expense export in Excel, assume columns A through D contain posting date, business unit, management cost class and positive expense amount. H1 holds the period start, I1 the next period start, and H2 the selected unit:

=SUMIFS(D:D,A:A,">="&H1,A:A,"<"&I1,B:B,H2,C:C,"Variable")

Replace "Variable" with "Fixed" for the other cost class. Microsoft's SUMIFS documentation explains summing rows that meet multiple criteria. Check unmapped accounts separately; they must not disappear from the comparison. Covirage is not affiliated with Microsoft.

Work the comparison from units and rates

A US manufacturer compares August and September 2026. The input sheet uses columns A through G exactly as shown. Unit variable costs include all costs classified as variable for these products. The figures are illustrative operating assumptions, not industry benchmarks.

On each product row, calculate these four amounts in columns H through K:

H2 = B2*C2
I2 = E2*F2
J2 = B2*D2
K2 = E2*G2

Fill down through row 3. These columns are August revenue, September revenue, August variable cost and September variable cost, respectively. Their results are:

The expense ledger supplies fixed expenses of $60,000 in August and $65,000 in September. Adding them produces the operating comparison:

Operating margin is operating profit divided by revenue: 70,000 / 300,000 = 23.3%, versus 68,000 / 319,100 = 21.3%. Percentages are rounded to one decimal place; dollar calculations retain full precision. Sales increased, but the added contribution did not cover the fixed expense increase.

Explain the profit movement without counting it twice

Use prior-period unit contribution for the quantity effect. Apply price and variable unit cost changes to current-period quantities. This order assigns their interaction to the current-rate effects and creates an exact bridge.

On the input sheet, add these columns and fill down:

L2 = (E2-B2)*(C2-D2)
M2 = E2*(F2-C2)
N2 = -E2*(G2-D2)

The proof is 70,000 + 3,000 + 9,100 − 9,100 − 5,000 = $68,000. The residual, ending profit minus starting profit minus all effects, is zero. The quantity line includes changes in product composition; do not add another mix line without first splitting that same quantity effect.

The sales team owns the lower seal-kit volume and realized prices. Procurement and operations investigate higher unit costs. Finance identifies the fixed expense accounts behind the increase and checks timing before proposing a spending action. A separate revenue driver analysis can expand the sales movement by customer without changing this profit bridge.

Where it goes wrong

• Treating cash payments as expenses. Supplier payments and customer receipts belong to a cash comparison. Mixing them with recognized revenue distorts operating profit.
• Calling every production cost variable. Cost location and cost behavior are different classifications. Fixed factory costs still need to appear once in the reconciliation.
• Allocating overhead differently between periods. A changed allocation can move unit profit without changing company expense. Show the allocation effect separately.
• Adding growth and mix effects twice. Product-level quantity effects already reflect changes in composition. Use a documented bridge order and test the residual.
• Ignoring credits or unmatched costs. Include returns, rebates and late cost postings, then tie both periods to the closed ledger before explaining performance.

Compare your own sales and expenses in Covirage

Bring a sample of your own sales export and expense ledger, with periods, business units and cost classifications. Covirage maps the columns, and its tools compute the comparisons and check the reconciliation; the external AI model explains the results with every figure traced to its rows. Create a free Covirage account and bring a sample of your own data.

See cost variance analysis for the supporting approach to explaining expense movements.