--- title: Assignment calculator for temporary staffing — alluvo description: Calculate assignments in temporary staffing for free: compare contribution margin, term, billing rate and idle time. For staffing agencies. url: https://alluvo.ai/en/tools/assignment-calculator --- 1. [Free tools](https://alluvo.ai/en/tools) 2. Assignment calculator # Is the assignment worth it? Gross wage in, billing rate in, contribution margin out. And then the question behind it: one long assignment at a low rate, or short ones at a higher rate, with idle time and switching costs? No sign-up. The link is the comparison. ## One employee, one number What is left each month while the assignment runs? Two numbers are enough, everything else is below under "Adjust assumptions". **Your assignment today** **20** Gross wage per hour €/h The employee's agreed hourly wage, without on-costs. **42** Hourly billing rate €/h What the client pays per hour worked. Calculation sheet · per month 138.67 h billable[1] **Revenue per month** €5,824 **− Wage costs incl. on-costs** €4,245.60 **Contribution margin I** €1,578.40 **− Overhead per employee** €350 **Contribution margin II** €1,228.40 Faktor 2.10 Marge 21.1 % Break-even rate €33.14 ## Two assignment profiles over time The same employee, two paths. On the left the assignment that is running; on the right the offer on the table. Costs keep running during idle time, which is where most calculations in your head fail.[1] **Scenario A** **Long assignment** Name **€42** per hour on **€20** gross wage change above **0** Assignment length months 0 = continuous **0** Idle time afterwards working days per change **0** Switching costs € per new assignment **0** Pay rise from month 0 = none[2] **0** Increase by €/h Equal pay, surcharge[2] **261** assignment days · **0** idle · **0** changes End: **€14,740.80** **Scenario B** **Short assignments** Name **48** Billing rate €/h **20** Gross wage €/h **3** Assignment length months 0 = continuous **8** Idle time afterwards working days per change **600** Switching costs € per new assignment **0** Pay rise from month 0 = none **0** Increase by €/h Equal pay, surcharge **237** assignment days · **24** idle · **3** changes End: **€15,580.25** - Long assignment €14,740.80 - Short assignments €15,580.25 Cumulative contribution margin over 12 months Month **12.0** Long assignment: **€14,740.80** Short assignments: **€15,580.25** Differenz: **+ €839.45** Over 12 months "Short assignments" leaves €839.45 more than "Long assignment". It is only settled from month 11.0: before that the lead changes with every new assignment. [3] **The lever on the rate** "Long assignment" would need at least **€42.50** per hour to catch up. **The lever on idle time** "Short assignments" tolerates at most **8** idle days per change. **Month by month** | Month | Long assignment | Short assignments | Difference | | --- | --- | --- | --- | | 1 | €1,242.52 | €2,084.08 | + €841.56 | | 2 | €2,485.04 | €4,168.17 | + €1,683.13 | | 3 | €3,671.08 | €6,157.52 | + €2,486.44 | | 4 | €4,913.60 | €5,193.42 | + €279.82 | | 5 | €6,156.12 | €7,277.50 | + €1,121.38 | | 6 | €7,398.64 | €9,361.58 | + €1,962.94 | | 7 | €8,584.68 | €8,302.75 | − €281.93 | | 8 | €9,827.20 | €10,386.83 | + €559.63 | | 9 | €11,069.72 | €12,470.91 | + €1,401.19 | | 10 | €12,312.24 | €12,412.84 | + €100.60 | | 11 | €13,498.28 | €13,496.17 | − €2.11 | | 12 | €14,740.80 | €15,580.25 | + €839.45 | **Adjust assumptions** **Shared assumptions for both scenarios** They apply to both scenarios. The presets are approximations common in the industry, not collective-agreement values; if you know your own, enter them.[4] **40** Weekly hours h **22** Payroll on-costs % **30** Vacation days per year days **12** Sick days days **11** Public holidays on weekdays days **350** Overhead per month € **12** Period under review months This gives **174** paid hours per month, of which **79.7 %** billable, and **261** working days in the period under review. alluvo calculates this for every assignment, from the framework contract and the timesheet, not from a form. [See the product](https://alluvo.ai/en/product) [Get to know alluvo](https://alluvo.ai/demo) More tools - [Billing rate calculator What is the least you have to charge the client?](https://alluvo.ai/en/tools/billing-rate) - [Bench cost calculator What does the bench cost you each month?](https://alluvo.ai/en/tools/bench-cost) - [Payment term cash-flow calculator How much cash does a client tie up with 45 days to pay?](https://alluvo.ai/en/tools/cash-flow) [See all tools](https://alluvo.ai/en/tools) ## Footnotes 1. How it is calculated: it works in working days, 261 a year, 21.75 a month. All working days are paid, but only the days the employee is at the client can be billed: vacation, sickness and public holidays are deducted. Wage and overhead costs **keep running even when idle**, because bench time is paid time. Switching costs arise at the start of every assignment except the first; the first assignment costs the same in both scenarios and drops out of the comparison. ↩ 2. Pay rise: applies from the stated month for the rest of the period, including across a change of assignment. This is deliberately kept simple: the real steps of industry surcharges and the equal-pay date depend on the collective agreement and the client's business, not on a number in a form. ↩ 3. Break-even: the *last* change of lead is shown, not the first. With short assignments the two curves overtake each other several times; any statement before the last change would be wrong again on the next change day. ↩ 4. What this calculator cannot do: surcharge steps under an industry surcharge agreement, collective-agreement specifics, surcharges for night, Sunday and holiday work, VAT, factoring and payment terms. It is a back-of-the-envelope calculation for a conversation, not tax or legal advice. ↩