LegalCalculatorTools

Legal Retainer Calculator

Size a retainer against the work expected, and set a replenishment trigger that keeps the matter moving.

Last reviewed

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Free · No sign-up · Runs in your browser

A retainer that is too small runs out mid-matter and stops the work at the least convenient moment. One that is too large is a barrier at the point the client is deciding whether to instruct you at all.

This calculator sizes the deposit against the work actually expected, then sets a replenishment trigger high enough that funds are requested before they run out rather than after.

Your numbers

Results update as you type. Nothing is sent anywhere.

Result

Retainer amount

$7,500

Request replenishment at

$1,875

Estimated fees
$7,000
Expenses
$500
Monthly burn rate
$2,500
Months until the trigger
2.3
Hours covered
20
Hours per month
6.7

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

A replenishment trigger set well above zero keeps work from stopping while funds are requested. Twenty-five percent of the original deposit is a common choice.

Client funds handling is regulated. Trust accounting, earned-on-receipt language and refundability all depend on your jurisdiction and your bar rules.

How to use the legal retainer calculator

  1. Enter the estimated hours for the phase the retainer is meant to cover.
  2. Enter the hourly rate and any expenses expected in that period.
  3. Enter how many months the work is expected to span.
  4. Set the replenishment threshold, then read the trigger point and the burn rate.

What people use this for

  • Setting the deposit figure for an engagement letter.
  • Deciding when to request replenishment on an active matter.
  • Explaining to a client why the retainer is the size it is.
  • Planning cash flow across several matters at once.

Worked examples

Every figure below is produced by running this calculator against the example inputs, so the numbers always match the tool.

An opening phase

20 estimated hours at $350, $500 of expenses, expected to span three months, replenishing at 25%.

Retainer amount
$7,500
Request replenishment at
$1,875
Months until the trigger
2.3

A larger matter with a higher trigger

Sixty hours over six months with the replenishment trigger set at 40%.

Retainer amount
$23,000
Monthly burn rate
$3,833
Months until the trigger
3.6

Set the trigger well above zero

A replenishment request takes time to reach the client, be considered, and be paid. If the trigger is set at zero the work stops while that happens, and stopping mid-matter is expensive for everyone.

Twenty-five percent of the original deposit is a common choice because it usually buys several weeks at typical burn rates. The right figure depends on how fast the matter is consuming funds, which is what the burn rate in the results is for.

Client funds are regulated

How a retainer is held, whether it is earned on receipt, whether it must sit in a trust account, when it can be drawn against and what happens to an unearned balance are all governed by professional conduct rules, and those rules differ by jurisdiction.

This calculator sizes an amount. It does not tell you how to hold it, and getting that part wrong is a regulatory problem rather than a commercial one.

Methodology and assumptions

What this calculator does, and what it deliberately does not do.

  • The retainer is estimated hours × rate, plus expenses. The burn rate divides that by the months the work is expected to span.
  • The replenishment trigger is the threshold percentage applied to the original retainer amount.
  • Trust accounting requirements and refundability are jurisdiction specific and are not modelled.
  • The tool performs arithmetic or date counting on the values you enter. It does not interpret a rule, a statute or a contract.
  • Nothing you type is transmitted or stored - the calculation runs entirely inside your browser.

This website provides general informational and productivity tools and does not provide legal advice or create an attorney-client relationship.

The date and deadline tools count days exactly as you instruct them. They do not interpret court rules, statutes of limitation, filing requirements or any other legal authority, and they do not know the rules of your jurisdiction.

Always verify any date, fee, or calculation against the governing rule, the court calendar and your own professional judgement. If you need legal advice, consult a lawyer licensed in your jurisdiction.

Frequently asked questions

Is a retainer the same as a deposit?

Terminology varies by jurisdiction. In many places a retainer is an advance against fees held in trust and drawn down as work is done; in others the word describes a non-refundable engagement fee. The engagement letter should say which.

What happens to an unused balance?

In most jurisdictions unearned funds are returned to the client at the conclusion of the matter. Local conduct rules govern.

Should the retainer cover the whole matter?

Rarely, and rarely usefully. Sizing it to a defined phase keeps the number manageable and gives both sides a natural checkpoint.

Can I take the retainer as payment straight away?

That depends entirely on your jurisdiction and on how the engagement letter is worded. Drawing on client funds before they are earned is one of the most serious professional conduct failures.

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