Botox (onabotulinumtoxinA) is dosed in units, not millilitres, and the number of units required varies significantly by treatment area and muscle strength. Underdosing produces weak or short-lived results; overdosing creates an unnatural, frozen appearance and increases the risk of ptosis.
This calculator uses FDA-approved Allergan dosing for the three approved areas (forehead, glabella, crow's feet) and published provider guidelines for off-label areas. It adjusts for muscle mass and flags the 400-unit maximum safe cumulative dose per three-month interval.
Botox Unit Calculator
Botox Unit Estimator by Area
Based on FDA-approved Allergan dosing, the "Look of 3" labelling, and published provider guidelines. Select treatment areas.
Strong muscles require ~25% more units; fine muscles ~25% fewer
FDA-approved area reference
| Area | Typical units | Duration | Status |
|---|---|---|---|
| Forehead | 10–30u | 3–4 months | FDA |
| Glabella (11s) | 15–40u | 3–4 months | FDA |
| Crow's Feet | 12–30u | 3–4 months | FDA |
| Bunny Lines | 5–10u | 3–4 months | Off-label |
| Brow Lift | 2–6u | 3–4 months | Off-label |
| Lip Flip | 4–8u | 2–3 months | Off-label |
| Chin (dimpling) | 4–10u | 3–4 months | Off-label |
| Platysmal Bands | 26–36u | 4–6 months | Off-label |
| Masseter (jaw slim) | 40–60u | 4–6 months | Off-label |
Estimated dosage
Typical total units
64u
Range: 37–100u (average muscle)
FDA-approved; always combine with glabella for brow balance
FDA-approved standard dose 20u; strongest muscles — often need more
FDA-approved: 24u total (12u/side at 3 sites × 4u)
3-month session cost
64u estimated
At 3 areas · refresh every 3–4 months
These results are estimates based on published clinical data and are for informational purposes only. They do not constitute medical advice, a diagnosis, or a treatment recommendation. Consult a licensed aesthetic practitioner before beginning any treatment. Individual results vary.
FDA-approved versus off-label Botox areas
The FDA has approved Botox Cosmetic for three facial areas: the forehead (20 units typical), glabella or '11 lines' (20 units), and crow's feet (24 units total, 12 per side). The 'Look of 3' — all three areas treated together — totals 64 units and is the standard full upper-face treatment at least three times per year.
Off-label areas include bunny lines (5–10u), brow lift (2–6u), lip flip (4–8u), chin dimpling (4–10u), platysmal bands (26–36u), and masseter slimming (40–60u). Off-label does not mean unsafe — it means the FDA has not formally reviewed the specific indication, but these uses are well-established in clinical practice.
Muscle mass and dosing adjustments
Strong, expressive muscles require approximately 25% more units to achieve the desired effect. Fine, delicate muscles require approximately 25% fewer. The masseter muscle in particular requires high doses (40–60 units) because it is one of the strongest muscles in the body, but it also metabolises Botox more slowly, lasting 4–6 months versus the typical 3–4.
The maximum safe cumulative dose is 400 units per three-month interval. If your selected areas exceed this, the calculator will flag it — your provider should spread the treatments across multiple sessions rather than administering everything at once.