How to read this calculator
Enter the measurements, or press Simulate to load a case from the reviewed validation catalog. The calculator then shows:
- Results: Volume for centile comparison (0.5 × L × W × AP) and Ellipsoid volume (π/6 × L × W × AP) as plain numbers, with no interpretation attached.
- Age-reference centiles: Reference: Kelsey 2016, ages 0–40 years, predominantly transabdominal ultrasound with additional paediatric MRI data. A centile band does not diagnose or exclude uterine disease.
Decision steps: age-30 and age-0 reference rows
Radikulus compares the unrounded 0.5-formula volume with the published rounded limits. Equality at the 2.5th centile enters the lower outer band; equality at the 97.5th enters the upper outer band. Equality at the 16th, 50th or 84th enters the higher inner band. These are site conventions.
| Step | Criterion | Meaning | Detail |
|---|---|---|---|
| U-LOW | ≤ 23.9 mL (Table 5 lists 0 mL for age 0) | At or below the 2.5th centile | At or below the published lower reference limit. This is not a diagnostic cutoff. |
| U-IN | > 23.9 and < 206 mL (> 0 and < 5 mL for age 0) | Between the 2.5th and 97.5th centiles | The authors describe the outer model limits as an approximately 95% reference range. Being within them does not exclude uterine disease. |
| U-HIGH | ≥ 206 mL (≥ 5 mL for age 0) | At or above the 97.5th centile | At or above the published upper reference limit. This is not a diagnostic cutoff. |
Age-reference centiles
Kelsey et al. (PLoS One, 2016) derived and validated a normative model of uterine volume from birth to age 40 years, using MRI data from healthy young females and data from four transabdominal ultrasound studies of healthy females. Age alone accounted for about 84% of the variation in uterine volume up to age 40.
In this model, uterine volume increases across childhood, with a faster increase in adolescence reflecting the influence of puberty, followed by a slow but progressive rise during adult life.
Reference centiles are not available beyond age 40 in this model, which was censored at 40 because only 2 of its 1,418 observed measurements were from older women.
For centile comparison, the calculator uses 0.5 × L × W × AP, the formula Kelsey reports for the four extracted ultrasound studies. The additional MRI volumes were measured by segmentation and slice summation.
Radikulus compares the unrounded 0.5-formula volume with the published rounded limits. Equality at the 2.5th centile enters the lower outer band; equality at the 97.5th enters the upper outer band. Equality at the 16th, 50th or 84th enters the higher inner band. These are site conventions.
The adult observations in Kelsey’s extracted dataset were dominated by one Brazilian transabdominal ultrasound study, Gadelha Da Costa 2004, which included parous women. The model does not provide parity-specific centiles.
These comparisons are not established pregnancy or postpartum reference ranges.
Kelsey 2016 Table 5
| Age | 2.5th centile | 16th centile | 50th centile | 84th centile | 97.5th centile |
|---|---|---|---|---|---|
| 0 | 0.0 | 0.2 | 1.1 | 2.6 | 5.0 |
| 1 | 0.0 | 0.3 | 1.3 | 2.9 | 5.5 |
| 2 | 0.0 | 0.4 | 1.4 | 3.1 | 5.8 |
| 3 | 0.0 | 0.4 | 1.5 | 3.2 | 6.1 |
| 4 | 0.0 | 0.5 | 1.6 | 3.4 | 6.4 |
| 5 | 0.0 | 0.5 | 1.6 | 3.5 | 6.6 |
| 6 | 0.0 | 0.6 | 1.7 | 3.6 | 6.7 |
| 7 | 0.0 | 0.6 | 1.7 | 3.7 | 6.9 |
| 8 | 0.0 | 0.7 | 1.8 | 3.9 | 7.2 |
| 9 | 0.1 | 0.8 | 2.1 | 4.4 | 8.0 |
| 10 | 0.4 | 1.3 | 3.0 | 5.9 | 10.5 |
| 11 | 1.3 | 2.8 | 5.5 | 10.2 | 17.8 |
| 12 | 3.6 | 6.7 | 12.2 | 21.6 | 37.0 |
| 13 | 7.8 | 13.8 | 24.4 | 42.6 | 72.3 |
| 14 | 12.3 | 21.3 | 37.2 | 64.5 | 109.0 |
| 15 | 15.0 | 25.8 | 44.9 | 77.8 | 131.2 |
| 16 | 16.1 | 27.7 | 48.2 | 83.3 | 140.5 |
| 17 | 16.5 | 28.3 | 49.3 | 85.2 | 143.7 |
| 18 | 16.7 | 28.6 | 49.8 | 86.1 | 145.3 |
| 19 | 16.9 | 29.0 | 50.4 | 87.2 | 147.0 |
| 20 | 17.2 | 29.5 | 51.3 | 88.7 | 149.6 |
| 21 | 17.6 | 30.2 | 52.5 | 90.8 | 153.1 |
| 22 | 18.1 | 31.1 | 54.0 | 93.4 | 157.4 |
| 23 | 18.7 | 32.1 | 55.8 | 96.4 | 162.4 |
| 24 | 19.4 | 33.2 | 57.7 | 99.7 | 168.1 |
| 25 | 20.1 | 34.5 | 59.8 | 103.3 | 174.1 |
| 26 | 20.9 | 35.7 | 62.0 | 107.1 | 180.4 |
| 27 | 21.7 | 37.0 | 64.3 | 111.0 | 186.9 |
| 28 | 22.4 | 38.4 | 66.5 | 114.8 | 193.5 |
| 29 | 23.2 | 39.6 | 68.7 | 118.6 | 199.9 |
| 30 | 23.9 | 40.9 | 70.9 | 122.3 | 206.0 |
| 31 | 24.6 | 42.0 | 72.9 | 125.8 | 211.9 |
| 32 | 25.3 | 43.1 | 74.7 | 128.9 | 217.2 |
| 33 | 25.9 | 44.1 | 76.4 | 131.8 | 222.1 |
| 34 | 26.4 | 45.0 | 77.9 | 134.3 | 226.3 |
| 35 | 26.8 | 45.7 | 79.1 | 136.5 | 229.9 |
| 36 | 27.1 | 46.2 | 80.1 | 138.2 | 232.8 |
| 37 | 27.3 | 46.6 | 80.8 | 139.4 | 235.1 |
| 38 | 27.4 | 46.8 | 81.2 | 140.3 | 236.7 |
| 39 | 27.4 | 46.9 | 81.4 | 140.8 | 237.7 |
| 40 | 27.3 | 46.7 | 81.3 | 140.8 | 238.2 |
These are whole-year reference rows. The model includes extracted ultrasound volumes and additional MRI segmentation volumes; it is not stratified by pubertal stage or parity.
Worked example
Syed et al. (2021) reported a uterus described as normal size, measuring 73 × 40 × 42 mm on ultrasound in a 19-year-old with fallopian-tube torsion and a paraovarian cyst. The 0.5-formula estimate is 0.5 × 7.3 × 4.0 × 4.2 = 61.32 mL. Using Kelsey 2016 Table 5, age 19, it falls between the 50th-centile value of 50.4 mL and the 84th-centile value of 87.2 mL. The π/6 estimate is 64.21 mL.
| Item | Value |
|---|---|
| Dimension 1 | 73 mm |
| Dimension 2 | 40 mm |
| Dimension 3 | 42 mm |
| Age at scan (years) | 19 |
| Volume for centile comparison (0.5 × L × W × AP) | 61.32 mL |
| Ellipsoid volume (π/6 × L × W × AP) | 64.21 mL |
Reference: Kelsey 2016, ages 0–40 years, predominantly transabdominal ultrasound with additional paediatric MRI data. A centile band does not diagnose or exclude uterine disease.
Measurement and clinical context
Kelsey and colleagues propose age-reference uterine volumes as an adjunct when assessing disorders of sex development, prepubertal vaginal bleeding, precocious puberty and delayed menstruation. Their model uses age rather than pubertal stage and does not diagnose these conditions.
The 2024 joint pelvic ultrasound parameter evaluates overall uterine length sagittally from fundus to cervix, to the external os if identifiable, with outer-to-outer straight-line or trace measurement. AP depth is measured perpendicular to the endometrial longitudinal axis, and maximum width transversely or coronally. Corpus-only measurements exclude the cervix; the parameter notes that corpus volume is an estimate because no sonographic landmark defines the corpus–cervix boundary. The length definitions in Kelsey’s four pooled studies remain unconfirmed in this review.
Postmenopausal context
Uterine volume changes around menopause. Li et al. (2020) reported that volume began decreasing before the final menstrual period and was 20% and 35% lower in the first and second postmenopausal years than in that baseline year; the pattern was fairly consistent among women without uterine fibroids. Dias et al. (2020) reported a median uterine volume of 18.1 mL among 815 asymptomatic postmenopausal Sri Lankan women aged 45–74 who had never used hormone replacement therapy. These cohort summaries do not supply calculator thresholds.
Frequently asked questions
How is uterine volume calculated?
The centile comparison uses length × width × AP depth × 0.5. The calculator also shows the ellipsoid estimate using π/6 (≈0.5236), which is 4.72% higher. For dimensions 8 × 5 × 4 cm, these estimates are 80.00 and 83.78 mL, respectively.
What is a normal uterine volume?
There is no single normal uterine volume. Kelsey’s 50th-centile reference values are 49.8 mL at age 18, 70.9 mL at age 30 and 81.3 mL at age 40. These age-reference values are not diagnostic cutoffs and are not adjusted for pubertal stage or parity.
Does gravidity affect uterine size?
Yes. In an ultrasound study of 5,466 non-pregnant uteri without reported abnormal findings, greater gravidity was associated with greater uterine length, width and anteroposterior diameter.
How do you measure the uterus on ultrasound?
The 2024 joint pelvic ultrasound parameter evaluates overall uterine length sagittally from fundus to cervix, to the external os if identifiable, with outer-to-outer straight-line or trace measurement. AP depth is measured perpendicular to the endometrial longitudinal axis, and maximum width transversely or coronally. Corpus-only measurements exclude the cervix; the parameter notes that corpus volume is an estimate because no sonographic landmark defines the corpus–cervix boundary.
References
- Kelsey TW, Ginbey E, Chowdhury MM, Bath LE, Anderson RA, Wallace WH. A validated normative model for human uterine volume from birth to age 40 years. PLoS One. 2016;11(6):e0157375. doi:10.1371/journal.pone.0157375. PMID 27295032. PMC4905658.
- Verguts J, Ameye L, Bourne T, Timmerman D. Normative data for uterine size according to age and gravidity and possible role of the classical golden ratio. Ultrasound Obstet Gynecol. 2013;42(6):713-717. doi:10.1002/uog.12538. PMID 23754297.
- ACR–ACOG–AIUM–SPR–SRU. Practice Parameter for the Performance of Ultrasound of the Female Pelvis, revised 2024: https://www.acr.org/-/media/ACR/Files/Practice-Parameters/US-Pelvis.pdf
- Gadelha Da Costa et al. Uterine volume in adolescents. Ultrasound Med Biol 2004;30:7–10. doi:10.1016/j.ultrasmedbio.2003.09.009. PMID 14962602.
- Badouraki et al. J Clin Ultrasound 2008;36:539–544. doi:10.1002/jcu.20522. PMID 18726968.
- Li et al. Menopause 2020. PMID 32132441: https://pubmed.ncbi.nlm.nih.gov/32132441/
- Dias et al. Post Reprod Health 2020. PMID 32308115: https://pubmed.ncbi.nlm.nih.gov/32308115/
- Syed et al. Fallopian Tube Torsion Secondary to Paraovarian Fimbrial Cyst: A Difficult to Diagnose and a Rare Cause of Acute Abdomen in Adolescent. Cureus 2021;13:e17888. doi:10.7759/cureus.17888. PMID 34660087.