Calculator Inputs
Example Data Table
| Project | Regular Hours | OT Hours | Break Hours | Non-Billable | Rate | Write-Off | Discount | Billable Hours | Invoice Total |
|---|---|---|---|---|---|---|---|---|---|
| Website Redesign | 40 | 6 | 2 | 5 | $85 | 8% | 3% | 39 | $3,650.63 |
| Mobile App Sprint | 35 | 4 | 1 | 3 | $95 | 5% | 2% | 35 | $3,625.72 |
| Marketing Launch | 30 | 2 | 1.5 | 4 | $70 | 10% | 0% | 26.5 | $1,994.50 |
Formula Used
1. Adjusted Regular Hours
Adjusted Regular Hours = Regular Hours − Break Hours
2. Regular Billable Hours
Regular Billable Hours = Adjusted Regular Hours − Non-Billable Hours
3. Total Billable Hours
Total Billable Hours = Regular Billable Hours + Overtime Hours
4. Gross Labor Revenue
Gross Labor Revenue = (Regular Billable Hours × Hourly Rate) + (Overtime Hours × Hourly Rate × Overtime Multiplier)
5. Write-Off Amount
Write-Off Amount = Gross Labor Revenue × Write-Off %
6. Discount Amount
Discount Amount = (Gross Labor Revenue − Write-Off Amount) × Discount %
7. Net Labor Revenue
Net Labor Revenue = Gross Labor Revenue − Write-Off Amount − Discount Amount
8. Invoice Total
Invoice Total = Net Labor Revenue + Reimbursable Expenses
9. Utilization Rate
Utilization Rate = (Total Billable Hours ÷ Tracked Hours) × 100
10. Effective Hourly Rate
Effective Hourly Rate = Net Labor Revenue ÷ Total Billable Hours
How to Use This Calculator
- Enter the project and consultant names for reporting clarity.
- Add regular hours, overtime hours, deducted break hours, and non-billable time.
- Enter the standard hourly rate and the overtime multiplier used in billing.
- Include write-off percentage, discount percentage, and reimbursable expenses if applicable.
- Set working days, utilization target, and project budget to evaluate performance.
- Press the calculate button to see the result summary above the form.
- Use the CSV or PDF buttons to export the final calculation.
FAQs
1. What are billable hours?
Billable hours are time entries you can charge to a client. They exclude unpaid breaks, internal meetings, admin work, and other non-billable activities not tied to a payable engagement.
2. Why track non-billable hours separately?
Separating non-billable time helps you understand workload efficiency, staff utilization, and hidden project overhead. It also shows where revenue leakage happens during delivery.
3. What is a write-off in billing?
A write-off is revenue removed before invoicing. It usually happens when time exceeds estimates, cannot be justified, or must be reduced to honor a client agreement.
4. What does realization rate mean?
Realization rate compares net labor revenue with gross labor revenue. It shows how much earned labor value remains after write-offs and discounts reduce the invoice.
5. How is utilization rate useful?
Utilization rate shows the share of tracked time that became billable. Higher utilization often means stronger resource efficiency, though quality and sustainability should also be considered.
6. Should reimbursable expenses be included?
Yes, when expenses are chargeable to the client. They do not increase billable hours, but they do increase the total invoice value collected from the project.
7. Can this calculator handle overtime billing?
Yes. Enter overtime hours and an overtime multiplier. The calculator bills those hours at the increased rate and adds that value to gross labor revenue.
8. Why compare invoice total with project budget?
Budget comparison shows whether billed value stays within the approved financial limit. It helps project managers spot overruns early and protect margins before invoicing closes.