LegalBillingTools

Free Legal Billing Calculators

Billing arithmetic, done where the client can follow it

Four calculators covering how legal work turns into money: an invoice with the discount and retainer shown as lines, a contingency split on either fee basis, hourly billing followed through to cash, and a retainer sized to its burn rate.

Open the Legal Invoice CalculatorBrowse all 4 tools

Legal Invoice Calculator

Assemble an invoice from time, flat fees and expenses, apply a discount and tax, and show the amount due after a retainer is applied.

Your numbers

Results update as you type. Nothing is sent anywhere.

Result

Invoice total

$6,861

Amount due

$2,861

Time fees
$6,290
Flat fee
$0
Discount applied
$629
Net fees
$5,661
Expenses
$1,200
Tax
$0
Retainer applied
$4,000
Retainer credit remaining
$0

This tool performs arithmetic on the values you enter. It does not provide legal advice and does not create an attorney-client relationship.

Showing the discount as a separate line makes the concession visible to the client rather than hiding it in a lower rate.

Tax treatment of legal fees and of disbursements differs by jurisdiction. Confirm which lines are taxable where you practise.

Read the full guide, worked examples and FAQ for this calculator →

Popular tools

The calculators visitors to LegalBillingTools open most often.

Legal billing generates disputes for a small number of recurring reasons: a total with no visible construction, a discount that was applied invisibly, a contingency percentage whose basis was never explained, or a retainer that ran out mid-matter.

Every one of those is an arithmetic presentation problem rather than a legal one. These calculators show the working, which is what makes the number defensible - both to a client asking a reasonable question and to a fee auditor asking a harder one.

Browse by category

Billing & Fees

Fee estimates, invoices, retainers and flat-fee pricing.

Why use LegalBillingTools

Invoices with the working shown

Time, flat fee, expenses, discount, tax and retainer as separate lines - so the total answers the obvious question before it is asked.

Contingency on either basis

Fee before or after costs can move a client’s net by thousands on the same recovery. Both are calculated so the difference is visible.

Billed versus collected

Realization and collection multiply, and the gap between recorded time and cash is routinely a fifth of the year.

Retainers sized to burn rate

A replenishment trigger is only useful if it buys enough time for the request to be made and paid at the matter’s actual pace.

How it works

  1. Assemble the invoice with each component as its own line.
  2. Apply the retainer against the total rather than folding it into the fees.
  3. Track realization and collection so the revenue figure means cash.
  4. Re-size the retainer whenever the matter’s pace changes.

Frequently asked questions

Is this legal advice?

No. This website provides general informational and productivity tools and does not provide legal advice or create an attorney-client relationship.

Does the contingency basis really matter?

Substantially. On a $250,000 recovery with $28,000 of costs, calculating a one-third fee before rather than after costs moves over $9,000 between the firm and the client.

Should I show discounts on the invoice?

Generally yes. A concession delivered by quietly reducing recorded hours is invisible, earns no goodwill, and tends to become the expected rate.

Are retainer rules the same everywhere?

No. Whether client funds must be held in trust, whether a retainer can be earned on receipt, and what happens to an unearned balance are governed by conduct rules that differ by jurisdiction.

Is anything I enter stored?

No. Every calculation runs in your browser. No client figures, recovery amounts or rates are transmitted or saved.