Working capital calculator for contractors
Works out the working capital locked in unbilled and uncertified work, the interest it costs a year, and what a shorter billing lag frees.
- Applies to
- Any contractor billing monthly against work done
- Rates
- Set per contract
- Last checked
- 10 November 2026
Inputs and result. Every rate is yours to set.
11% is the example's CC or OD rate. Use your own.
Interest saved a year
₹11,00,000
- Working capital locked today₹5,00,00,000
- Interest on it a year₹55,00,000
- Working capital freed₹1,00,00,000
- Growth, 8 work orders, a year₹2,39,904 plus GST
Rule applied. Working capital locked = billing value a month x (days from work done to bill + days from bill to certification) / 30. Interest a year = working capital locked x cost of funds. Saving = billing value a month x days cut / 30 x cost of funds.
Last checked 10 November 2026
The steps behind the figure
- Enter the value you bill in a month.
- Enter the days from work done to bill, and from bill to certification.
- Enter your cost of funds, the CC or OD rate.
- Enter the days you expect to cut from the billing lag, and read the saving a year.
| Description | This bill | Amount ₹ |
|---|---|---|
| Earthwork in excavation, foundationAll soils, lift up to 1.5 m | 165.30 | 41,077.05 |
| PCC 1:4:8, 40 mm aggregateIn foundation and plinth | 14.25 | 91,371.00 |
| RCC M25 in slabs and beamsUp to floor five | 74.20 | 6,65,203.00 |
| Reinforcement, Fe 500DCut, bent and placed | 9,745 | 7,64,008.00 |
| Brickwork 1:6, superstructureModular bricks | 36.50 | 2,59,880.00 |
| 12 mm cement plaster 1:6Internal walls | 770.00 | 2,63,340.00 |
Why divide by 30?
Each 30 days of lag holds about one month's billing value as working capital. Fifteen days holds half a month.
Which cost of funds should I use?
The rate on the cash credit or overdraft that funds the gap, since that is the interest a shorter lag saves.
How is the plan cost worked out?
Starter is ₹4,999 a month billed yearly for up to 3 work orders. Growth is ₹2,499 per work order a month for 4 to 15. GST is extra.