| Item | Rate | Units | Occurrences | Item Total | Category |
|---|
Use this sample as a quick reference. You can load it into the calculator using Load Example.
| Item | Rate | Units | Occurrences | Category |
|---|---|---|---|---|
| Packaging | 0.12 | 1000 | 1 | Materials |
| Card Processing Fees | 0.025 | 25000 | 1 | Transaction |
| Shipping Labels | 0.08 | 1000 | 1 | Fulfillment |
| Sales Commissions | 0.03 | 40000 | 1 | Sales |
- Item Total = Rate × Units × Occurrences
- Subtotal = Sum of all item totals
- Adjustments = Subtotal × (Wastage% + Contingency%)
- Tax = (Subtotal + Adjustments) × Tax%
- Grand Total = Subtotal + Adjustments + Tax
- Per-Unit Expense = Grand Total ÷ Total Units
- Revenue = Selling Price × Total Units (optional)
- Contribution = Revenue − Grand Total (optional)
- Contribution Margin = Contribution ÷ Revenue (optional)
All percentages are applied as decimals (e.g., 5% = 0.05). Occurrences represent how many times the expense repeats within the selected period.
- Select Currency and the Analysis Period.
- Enter Total Units for the period (orders, items, billable hours, etc.).
- Add expense items with Rate, Units, and Occurrences.
- Optionally add Wastage, Contingency, and Tax percentages.
- Click Calculate to view results above the form.
- Use Download CSV or Download PDF for reporting.
1) Variable expense drivers by volume
Variable expenses scale with activity. If units rise from 10,000 to 12,500, a per-unit packaging cost of 0.12 increases from 1,200 to 1,500 in the same period. This calculator keeps the relationship explicit by applying rate × units × occurrences per item, then summarizing the subtotal and per-unit cost.
2) Handling mixed-rate expense types
Not every “rate” is per unit sold. Payment fees often use a percent of revenue, while shipping labels may be per order. Model them consistently by defining the unit base you control (orders, shipments, hours). For example, 2.5% processing on 25,000 revenue becomes rate 0.025 with units 25,000 and occurrences 1.
3) Adjustments for volatility and shrinkage
Real budgets include variability. A 1.5% wastage and 2% contingency on a 50,000 subtotal adds 1,750 before tax. The calculator separates “adjustments” so you can test sensitivity quickly and document assumptions in exports for approval workflows.
4) Per-unit variable expense benchmarking
Per-unit expense is the most portable metric for comparisons across months or product lines. If grand total is 67,500 and units are 25,000, per-unit variable expense is 2.70. Track this number to validate pricing, identify supplier drift, and flag operational inefficiencies.
5) Contribution analysis with optional selling price
When you enter selling price, the tool estimates revenue and contribution. Example: price 4.00, units 25,000 gives revenue 100,000. If grand total variable expense is 67,500, contribution is 32,500 and margin is 32.5%. This supports pricing decisions and break-even planning.
6) Using the Plotly Pareto chart for prioritization
The chart ranks items by total cost and plots cumulative share. If the first three items account for 78% of the grand total, focus negotiation, process changes, or automation on those drivers first. This approach helps teams reduce noise and target the few items that materially change unit economics.
1) What counts as a variable expense?
Costs that move with activity, such as packaging, payment fees, commissions, and per-order fulfillment. Fixed costs like rent or salaries should not be modeled here unless tied directly to units.
2) How do I model percentage-based fees?
Enter the percent as the rate (e.g., 0.025) and use revenue as the units for the period. This converts the fee into a consistent, item-level total.
3) What do occurrences mean?
How many times the item repeats within the selected period. Use 1 for monthly totals, 4 for weekly charges inside a month, or higher for per-batch costs.
4) Why add wastage or contingency?
They capture expected losses and uncertainty. This makes budgets more realistic, reduces surprise overruns, and provides a documented buffer for operational variability.
5) Does tax apply to every business case?
Not always. Some expenses are tax-exempt or recoverable. Use the tax field only when it reflects your effective cost after credits and recoveries.
6) What does the Pareto line tell me?
It shows how quickly costs concentrate. If the line reaches 80% with few items, improving those top drivers delivers the largest impact on total variable expenses.