Kirby-Desai Estimator

The Kirby-Desai scale is a scoring system that estimates how many laser sessions a tattoo will need to clear. You score the tattoo across six parameters — skin type, location on the body, amount of ink, layering, scarring, and colours — and add the scores together. The total is the estimated number of treatments.

That is the whole method: no weighting, no formula beyond addition. Its power is that it forces you to look at the six things that genuinely drive the outcome, rather than guessing from the size of the tattoo — which is what most people expect to matter, and which the scale does not score at all.

Size determines the price of a session. The six parameters below determine how many sessions you need. They are separate questions, and confusing them is the single most common mistake people make when budgeting for removal.

The scale was published in 2009 by William Kirby, Alpesh Desai and colleagues in The Journal of Clinical and Aesthetic Dermatology. They built it from a retrospective review of 100 patients treated at a tattoo-removal clinic in Beverly Hills between 2004 and 2008.

Scoring the tattoos in that group and comparing the totals against the number of sessions each actually needed produced a good correlation (r = 0.757, p < 0.001). In that group the average score was 9.87 and the average number of treatments was 9.91 (± 3.18, range 3–20) — the score and the reality tracked each other closely.

Full citation: Kirby W, Desai A, Desai T, Kartono F, Geeta P. The Kirby-Desai Scale: A Proposed Scale to Assess Tattoo-removal Treatments. The Journal of Clinical and Aesthetic Dermatology. 2009;2(3):32–37.

Each parameter contributes a fixed range of points, and the six are simply summed. The lowest possible total is 4 and the highest is 26 — so the scale is really saying "somewhere between a handful of sessions and a very long course".

The estimator above walks you through exactly these six questions. The table shows what each one can contribute and why it matters.

It is a good estimate and a bad promise. The original correlation (r = 0.757) is strong for a clinical scoring tool, but it is a correlation across a group — not a guarantee for any one tattoo. In the source study the actual number of treatments varied by roughly ± 3 around the average even as the scale tracked it well.

The reason is that the scale cannot score the thing that does most of the work: your immune system. The laser only fragments the ink. Your body carries the fragments away, and how fast it does that varies from person to person — which is why two people with identical scores can finish several sessions apart. Smoking, in particular, is well documented to slow clearance, and the scale does not score it.

The authors themselves flagged the limits of their sample: they wrote that "further studies with more subjects are still needed to confirm the reproducibility of this scale", noting that their clinic population may not have included enough difficult-to-treat tattoos — the heavily scarred and heavily layered ones — to test the scale properly at the hard end.

Treat the number as a planning figure. If the scale says ten, budget for something in the region of ten, expect to be told more at a consultation if your tattoo is unusual, and be pleased if your body clears it faster.

The scale predates the current generation of lasers. The study population was treated between 2004 and 2008 with Q-switched nanosecond lasers — Nd:YAG or Alexandrite — at 6 to 8 week intervals. Picosecond devices only reached the market years afterwards, so no picosecond-treated tattoo contributed to the original correlation. The six parameters still describe what makes a tattoo hard to remove regardless of device, but a score is not a device-independent count of sessions, and anyone quoting it as one is overstating it.

It does not score tattoo size, ink brand or chemistry, how deeply the ink was deposited, your age, your general health, or whether you smoke — all of which affect clearance. It also has nothing to say about how you should be treated: it estimates a number of sessions, not a treatment plan.

It also cannot tell you whether a tattoo can be fully removed at all. Some colours — particularly greens, blues, whites and pastels — may never clear completely with the wavelengths currently available, and a low score on a green tattoo is still a green tattoo.

Finally, the authors noted that scores above 15 warrant reassessment — a high score is a signal that the case is complex and deserves a careful in-person look, not just a longer course booked in advance.

We use the scale the way it was intended: as a starting point for an honest conversation, not as a quote. At your consultation and patch test we score your tattoo in person — which is more reliable than you scoring it from a screen, because judging ink density and existing scarring is genuinely hard to do on your own skin.

We then tell you what we actually think, including when the honest answer is that removal will be long, expensive, or not worth it for your tattoo. A patch test tells us how your skin and your ink really respond, and that single data point is worth more than any score.

You are welcome to use the estimator before you come in. It is free, it stores nothing, and it will give you a realistic sense of the scale of the commitment before you spend money finding out.