Bolton Tooth-Size Ratio
Bolton anterior and overall tooth-size ratios against 77.2% and 91.3%, with the excess in mm.
Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.
Example
- Maxillary canine-to-canine sum of widths
- 47.5 mm
- Mandibular canine-to-canine sum of widths
- 37.4 mm
- Maxillary first-molar-to-first-molar sum
- 96.4 mm
- Mandibular first-molar-to-first-molar sum
- 88.9 mm
Result: Anterior ratio (canine to canine) 78.7% against Bolton's 77.2% (SD 1.65): within 1 SD, a mandibular excess of 0.7 mm. Overall ratio (first molar to first molar) 92.2% against Bolton's 91.3% (SD 1.91): within 1 SD, a mandibular excess of 0.9 mm.
The tool opens with these values already filled in. Replace them with your own.
What you enter
- Maxillary canine-to-canine sum of widths
- Mandibular canine-to-canine sum of widths
- Maxillary first-molar-to-first-molar sum
- Mandibular first-molar-to-first-molar sum
How this is calculated
Citation
Bolton WA. Disharmony in tooth size and its relation to the analysis and treatment of malocclusion. Angle Orthod. 1958;28(3):113-130. Read the sources: J Clin Med 2026 ↗, Cureus 2026 ↗
A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.