Calculator
Example Data Table
| Client | Project | Rate | Regular Hours | Overtime Hours | Weekend Hours | Expenses | Retainer |
|---|---|---|---|---|---|---|---|
| North Ledger Co. | Quarterly Review | $95.00 | 28 | 4 | 1 | $85.00 | $200.00 |
| Acme Advisory | Payroll Cleanup | $85.00 | 32 | 6 | 2 | $120.00 | $250.00 |
| Bright Harbor LLC | Monthly Books | $78.00 | 18 | 0 | 0 | $40.00 | $100.00 |
Formula Used
Regular Billing = Regular Hours × Hourly Rate
Overtime Billing = Overtime Hours × Hourly Rate × Overtime Multiplier
Weekend Billing = Weekend Hours × Hourly Rate × Weekend Multiplier
Minimum Adjustment = Max(0, Minimum Billable Hours − Total Hours) × Hourly Rate
Labor Subtotal = Regular Billing + Overtime Billing + Weekend Billing + Minimum Adjustment
Pre-discount Subtotal = Labor Subtotal + Expenses + Late Fee
Discount Amount = Pre-discount Subtotal × Discount %
Adjusted Before Tax = Max(0, Pre-discount Subtotal − Discount − Retainer Credit − Write-off)
Tax = Adjusted Before Tax × Tax %
Grand Total = Adjusted Before Tax + Tax
Effective Hourly Rate = Grand Total ÷ Final Billable Hours
How to Use This Calculator
- Enter the client, project, and billing period details.
- Set the base hourly rate and minimum billable hours.
- Add regular, overtime, and weekend or holiday hours.
- Adjust multipliers for premium billing categories.
- Include expenses, discounts, retainer credits, write-offs, and late fees.
- Enter the tax percentage applied to the post-credit balance.
- Click Calculate Billing to show totals above the form.
- Use the CSV and PDF buttons to export the result summary.
FAQs
1. What does this hourly billing calculator measure?
It estimates invoice totals using billable hours, premium multipliers, expenses, credits, discounts, taxes, and write-offs. It helps accountants and service firms prepare clearer billing summaries.
2. Why include minimum billable hours?
Many service agreements guarantee a minimum charge even when tracked time is lower. This field adds that gap automatically so the final invoice matches policy.
3. How is overtime calculated here?
Overtime uses the base hourly rate multiplied by overtime hours and the overtime multiplier. A multiplier of 1.5 means time-and-a-half billing.
4. Can I use weekend and holiday rates?
Yes. Weekend or holiday work is separated from normal overtime. That lets you apply a distinct multiplier for premium support or urgent accounting tasks.
5. Are retainer credits applied before tax?
In this setup, retainer credits and write-offs reduce the subtotal before tax is added. That matches many invoice workflows, though local rules may vary.
6. What is the effective hourly rate?
It is the final invoice total divided by final billable hours. This gives a blended rate after credits, taxes, expenses, and premium adjustments.
7. Can this tool support scenario analysis?
Yes. Change rates, hours, discounts, or taxes, then recalculate. The updated totals and chart make it easy to compare billing scenarios quickly.
8. Does the export include the calculation breakdown?
Yes. The CSV export downloads the result table data, and the PDF export captures the visible result section, including key totals and chart.