Why the rate on the engagement letter is not the rate you earn
Three different ratios get called realisation in different firms, and confusing them is the reason the same practice can be described as running at 92% or at 67% depending on who is talking. This calculator keeps them separate and multiplies them, which is the only arrangement that produces a number you can bank.
Utilisation is billable hours over hours at work. It measures how much of your day reaches a client matter at all. Everything that does not — supervision, business development, pitching, training, firm administration, the conversation with a client that you decided not to record — comes out here.
Billing realisation is invoiced value over the standard value of recorded time. It measures what survives between the time entry and the bill: agreed discounts, write-downs by a billing partner who thinks eight hours on that research memo is not a client-facing number, and rates negotiated below list under a panel arrangement.
Collection is cash received over amount invoiced. It measures what survives after the bill goes out: disputed line items, negotiated reductions after the fact, slow payers who eventually pay less, and genuine bad debt.
Each is a proportion of a different base, so they compose by multiplication. Three numbers that each sound healthy in isolation — 78%, 92%, 94% — produce an overall realisation of 67.45%, because 0.78 × 0.92 × 0.94 = 0.674544.
What the multiplication implies for where to spend effort
Because the three stages multiply, the leverage of each is proportional rather than absolute. Improving collection from 94% to 98% is a 4.26% relative gain and raises the effective rate by 4.26%. Improving utilisation from 78% to 81.32% is also a 4.26% relative gain and raises the effective rate by exactly the same 4.26%. There is no stage that is inherently more valuable to fix; there is only the stage where a given proportional gain is easiest to achieve.
That reframes the usual argument. Firms tend to attack utilisation, because it feels like the stage under individual control, and it is the one that shows up in a chargeable-hours target. But utilisation is bounded from above by physics: a lawyer recording 95% of hours at work as billable is either not developing any business, not supervising anyone, and not training — or is recording time that will be written down at the next stage anyway, which moves the loss rather than removing it. Billing realisation and collection have no such ceiling and are usually the product of process rather than effort: what the engagement letter says, whether there is a retainer, how quickly bills go out, and how promptly an unpaid invoice is chased.
Watch the double-counting trap. If a supervisor writes down the junior's time on the invoice, the loss appears at the billing realisation stage. If the junior anticipates the write-down and records fewer hours, the identical loss appears at the utilisation stage instead. The overall realisation is the same. That is the reason to look at the chain rather than at any single ratio: a firm can move its headline write-down number to nearly zero without collecting a dollar more.
Worked example: a $350 rate at 2,080 hours
A lawyer bills at a standard rate of $350, works a nominal 2,080 hours a year, records 78% of those hours as billable, sees 92% of the standard value of that time survive to the invoice, and collects 94% of what is invoiced.
- Standard value of the year. 2,080 × $350 = $728,000. This is the list-price value of every hour spent at work, and nobody ever earns it.
- Billable hours. 2,080 × 78% = 1,622.4 hours. The 457.6 hours that are not billable are worth $160,160 at standard rates, and that is the first loss.
- Standard value of billable time. 1,622.4 × $350 = $567,840.
- Invoiced. $567,840 × 92% = $522,412.80. The write-downs cost $45,427.20.
- Collected. $522,412.80 × 94% = $491,068.03. Collection losses cost $31,344.77.
- Effective rate. $491,068.03 ÷ 2,080 = $236.09 per hour at work.
- Overall realisation. 0.78 × 0.92 × 0.94 = 0.674544, or 67.45%. Check it against the money: $491,068.03 ÷ $728,000 = 0.674544.
The three losses add to $160,160 + $45,427.20 + $31,344.77 = $236,931.97, which is exactly $728,000 − $491,068.03. The largest single one is utilisation, and it is larger than the other two combined — which is typical, and which is why a firm that only measures write-downs and bad debt is looking at the smaller half of its problem.
How to read the effective rate
The effective rate is the number to compare against anything. Against a fixed-fee quote: if a matter would take 30 hours and you would price it at $8,000, that is $266.67 an hour against an effective rate of $236.09, so the fixed fee is the better deal even though it looks like a discount off $350. Against a salary: multiply the effective rate by hours at work to get what a fee earner actually generates, and compare that against their cost including benefits, overheads and support. Against a contingency matter: the effective rate is the opportunity cost of every hour you put into it.
Overall realisation is the number to compare across time and across people. It is dimensionless, so it survives a rate increase. That matters, because a rate increase that raises the standard rate and lowers billing realisation by the same proportion has achieved nothing at all, and looking only at the rate card will not show it. If realisation falls every time rates go up, the market is telling you what it will actually pay.
Be careful about benchmarking against published survey figures for other firms. Realisation numbers are not defined consistently between firms, and the same practice can report very different figures depending on whether hours at work or a standard target denominator is used, and on whether write-downs are recorded against time or against the invoice. Your own trend over four quarters, computed the same way each time, is worth far more than someone else's absolute number.
Effective rate at a $400 standard rate
| Utilisation | Collection 85% | Collection 90% | Collection 95% | Collection 100% |
|---|---|---|---|---|
| 60% | $183.60 | $194.40 | $205.20 | $216.00 |
| 70% | $214.20 | $226.80 | $239.40 | $252.00 |
| 80% | $244.80 | $259.20 | $273.60 | $288.00 |
| 90% | $275.40 | $291.60 | $306.00 | $324.00 |
Read along a row to see what collection is worth and down a column to see what utilisation is worth. Because the factors multiply, moving from 80% to 90% utilisation and moving from 85% to 95.6% collection produce the same proportional gain.
What distorts a realisation number
- Using a target denominator instead of hours at work. Dividing billable hours by a 1,700-hour target rather than by hours actually worked produces a utilisation figure above 100% and hides the unbilled time entirely.
- Not recording time you know will be written down. This moves the loss from billing realisation to utilisation and leaves the effective rate unchanged, while making one ratio look much better.
- Counting billed but unpaid work as revenue. Work in progress and receivables are not cash. A firm growing its billings while its collection rate falls is lending money to its clients.
- Ignoring the cost of carrying receivables. An invoice paid in full after 180 days has a collection rate of 100% and has still cost you half a year of the money's use.
- Averaging across very different matter types. Panel work at a discounted rate and full-rate private client work have structurally different billing realisation. Blending them hides both.
- Treating a rate rise as a revenue rise. If realisation falls proportionally, collected revenue is unchanged. Track the effective rate, not the rate card.
How this connects to pricing and to contingency work
The effective rate is the input to almost every other pricing decision. If you set fees for your own practice, the freelance hourly rate calculator works from the other direction — target income and overheads up to a rate — and the two should agree once realisation is applied. For a firm rather than an individual, the billable utilization rate calculator isolates the first stage of the chain, and the loaded hourly cost calculator gives the cost side to set against the revenue side.
On contingency matters the effective rate is the opportunity cost. Every hour spent on a case taken at a percentage of recovery is an hour not billed at $236.09, so the case has to clear that hurdle across the whole expected life of the matter, weighted by the probability of recovering anything at all. The litigation expected value calculator does that arithmetic and can be run from the firm's side as easily as from the client's, and the contingency fee net settlement calculator shows what a given recovery actually produces after the fee and the case costs.
Finally, if slow payment rather than non-payment is the problem, price it. Money owed and unpaid has a time cost whatever the eventual collection rate, and the judgment interest calculator shows what a statutory rate does to an unpaid sum over time. A firm that would never lend at 0% is often doing exactly that through its receivables ledger.
Define your denominator before you benchmark
Every figure on this page divides by hours at work — the whole working year, billable and non-billable. Many published realisation statistics divide by a chargeable-hours target instead, which is a different and usually more flattering denominator. Before comparing your number against anyone else's, confirm which denominator they used. The one used here is the conservative choice, and it is the one that makes the effective rate directly comparable against a salary or a fixed fee.