Quarter-hour billing turns short work blocks into invoice units, and Everhour keeps approved time connected to billing.
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Billing in 15 minute increments answers one practical question: how many quarter-hour units should appear on the invoice, and what are those units worth at the agreed hourly rate? Each 15-minute unit equals 0.25 billable hour. Four units equal 1 hour. The calculation starts with approved work time, applies the rounding rule, then multiplies the billable hours by the client rate.
The result matters when you prepare invoices, review write-downs, compare billable and worked time, or explain a charge to a client. For U.S. professional services, amounts are normally stated in U.S. dollars. If the service is taxable, the tax input is state and local, not a federal VAT/GST or national sales-tax rate.
Convert each approved time entry into minutes, apply the 15-minute billing rule, divide the rounded minutes by 60, then multiply by the hourly rate. When the policy rounds up to the next quarter hour, 1 to 15 minutes becomes 0.25 hour, 16 to 30 minutes becomes 0.50 hour, 31 to 45 minutes becomes 0.75 hour, and 46 to 60 minutes becomes 1.00 hour.
For example, a review project has 33 billable quarter-hour units after approved entries are rounded under the client policy. The billable hours are 33 × 0.25 = 8.25 hours. At a $140 hourly rate, the charge is 8.25 × $140 = $1,155. Any tax is added only when the state or local rule makes that service taxable.
The most common mistake is rounding the grand total instead of applying the agreed increment to each entry. If ten separate 7-minute entries are rounded up per entry, each becomes 15 minutes, for 150 billable minutes. If you total first, the same raw 70 minutes rounds to 75 minutes. That is half the invoice value of the per-entry method.
The right method is the one stated in the engagement terms, client contract, or billing policy. For U.S. lawyers, ABA Model Rule 1.5 requires the scope of representation and the basis or rate of fees and expenses to be communicated in writing for new client-lawyer relationships, subject to the rule's limited low-cost exception. Write the increment and rounding method plainly.
A quarter-hour total is not always the final amount due. First calculate the billable value from rounded hours and rate. Then apply discounts, write-downs, expenses, and jurisdiction-specific tax only where they apply. The United States has no federal VAT/GST, and sales tax treatment is state and local. A national tax percentage does not belong in a U.S. billable-hours formula.
State examples show why the tax field must stay jurisdiction-specific. Hawaii applies a general excise tax to business activities, generally 4% for most activities, with county surcharge pass-through caps reaching 4.7120% in counties that adopted the surcharge. New Mexico gross receipts tax includes performing services in New Mexico, with combined rates from 5.125% to 8.6875% by business location.
A calculator is enough when you need a one-time check: rounded billable units, hourly rate, invoice subtotal, and any known state or local tax input. It is also enough for reviewing a small invoice before sending it. The risk starts when entries come from multiple people, different rates, task-level exclusions, write-downs, or recurring client billing.
A managed workflow is better when the quarter-hour total must connect to approval, billing status, and invoice creation. Everhour Billing & Invoicing turns tracked billable time and expenses into client invoices, calculates invoice amounts from rates while excluding non-billable work, and can export invoices to QuickBooks Online, Xero, or FreshBooks.
This content is for general information only, may not be fully up to date, and is provided without any warranty or liability.
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One 15 minute billing unit is 0.25 hour. Two units are 0.50 hour, three units are 0.75 hour, and four units are 1.00 hour. To calculate the charge, multiply the number of quarter-hour units by 0.25, then multiply the result by the hourly rate.
Use the method stated in the client agreement, engagement letter, or billing policy. Rounding each entry usually produces a higher billable total than rounding the final daily or project total. The invoice should follow one method consistently, because switching methods changes the billed amount even when the raw work time is the same.
The formula is rounded billable units × 0.25 × hourly rate. If the rounded time equals 33 quarter-hour units and the hourly rate is $140, the billable amount is 33 × 0.25 × $140 = $1,155. Add state or local tax only when the service is taxable in the relevant jurisdiction.
No. Non-billable work should stay out of the invoice total even if it is tracked for internal reporting. Round only the approved entries that the client agreement treats as billable. Keeping non-billable work visible separately helps you calculate utilization and effective billing rate without charging the client for excluded time.
No. The United States has no federal VAT/GST or national sales-tax rate for billed professional time. Sales tax treatment is state and local, and different jurisdictions tax different goods or services. Use a jurisdiction-specific tax input only when the billed service is taxable.
Everhour Billing & Invoicing converts tracked billable time and expenses into invoices, calculates invoice amounts from rates, and excludes non-billable tasks. Invoices can be customized, tied to client settings, and exported to QuickBooks Online, Xero, or FreshBooks with invoice status synced back to Everhour.
Track billable entries, exclude non-billable tasks, and generate invoices from approved work instead of rebuilding totals by hand. Everhour keeps quarter-hour billing connected to Everhour Billing & Invoicing.
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