An attorney retainer is an advance deposit paid by a client into a dedicated trust or IOLTA (Interest on Lawyers Trust Accounts) escrow account. As legal work is performed, the law firm bills against this deposit based on hourly billing increments. Tracking retainer drawdown allows legal teams and clients to anticipate when trust reserves will be exhausted and when replenishment payments are required to maintain ongoing representation.

### Retainer Drawdown Mechanics and Formulas In typical legal fee agreements, retainer depletion follows predictable billing rates:

- **Available Billable Hours:** Total Retainer Deposit / Hourly Billing Rate - **Projected Burn Rate:** Weekly Billable Hours * Hourly Billing Rate - **Evergreen Replenishment Floor:** A predetermined dollar threshold (typically 20% to 30% of the initial deposit) that triggers a replenishment notice before the balance reaches zero.

### Tool Implementation Notice The interactive calculator on this page provides a client-side ratio modeling framework using three parameters: Primary Dimension / Load (Value 1), Operating Coefficient (Value 2), and Safety / Rate Factor (Value 3). It computes the primary ratio (Value 1 * Value 2) / Value 3, geometric mean sqrt(Value 1 * Value 2), and allocation percentage Value 1 / (Value 1 + Value 2). This calculator is an arithmetic modeling utility; it does not connect to legal practice management systems (such as Clio, MyCase, or PracticePanther), does not parse tenths-of-an-hour (0.1-hour / 6-minute) billing ledgers, and does not maintain formal bar-compliant trust accounting records.

### Worked Numeric Example A client deposits an evergreen retainer of $5,000 for representation with a lead counsel billing $350 per hour:

1. **Funded Hours:** $5,000 / $350 per hour = 14.29 total billable hours. 2. **Weekly Drawdown:** If discovery motions require 5 hours of work in a given week, weekly billing is 5 * $350 = $1,750. 3. **Remaining Balance:** After week one, the trust balance declines to $5,000 - $1,750 = $3,250 (9.29 billable hours remaining). 4. **Replenishment Trigger:** If the agreement stipulates an evergreen minimum balance of $1,500, replenishment is required once remaining funds reach approximately 4.3 billable hours.

### Client-Side Privacy Note All calculations operate strictly in your local browser runtime using React component state. Zero financial inputs, hourly rates, case details, or client data are ever transmitted across the network or stored on any server.