How to read this calculator
Enter three ultrasound dimensions for one testis or both, in cm or mm; the unit applies to both. Complete or clear any partly filled testis. Select Adult to compare 0.52 volumes with the ESUR-SPIWG 2025 hypotrophy limits: right <12 mL and left <11 mL. No comparison is made with Lambert, under 18, or while Reference comparison is unanswered.
How the volume is calculated
By default, each testis’s ultrasound volume is estimated as 0.52 × length × width × height, with dimensions in cm and volume in mL. ESUR-SPIWG 2025 suggests 0.52 × L × W × H for testicular ultrasound volume in adult male infertility evaluation; the formula recommendation is weak. The ACR–AIUM–SPR–SRU and AIUM scrotal ultrasound parameters, revised 2025, permit Lambert’s formula, 0.71 × L × W × H. Report the diameters and formula used. For the same diameters, Lambert gives approximately 1.365 times the 0.52 volume. For identical dimensions, the 0.52 estimate is approximately 0.69% lower than the π/6 estimate.
Hypotrophy limits
ESUR-SPIWG 2025 states that right testicular volume <12 mL or left volume <11 mL indicates testicular hypotrophy in male infertility evaluation. The limits were obtained with the 0.52 ellipsoid formula. They are the lower reference limits (5th percentiles) from 248 healthy, fertile men aged 23–53 in the EAA ultrasound study (Lotti 2021); study eligibility began at 18. Radikulus convention: this calculator compares any adult’s volume with these limits when Adult and Ellipsoid (0.52) are selected. This broader comparison does not establish that the limits are validated in every adult population. Exactly 12 mL on the right or 11 mL on the left is not below the limit. These limits are not applied to Lambert volumes or under 18.
How to measure
In the EAA study the three maximum diameters of each testis were measured: height (anterior–posterior) and width (transverse) on a transverse scan, and length on a longitudinal scan (Lotti 2021).
Accuracy
In Sakamoto’s study of 40 testes from 20 older men undergoing orchiectomy for prostate cancer, Lambert had the smallest mean difference from water-displacement volume.
Worked example
In a published case describing a 22-year-old man, scrotal ultrasound dimensions were 31 × 20 × 15 mm on the left and 23 × 14 × 13 mm on the right (Fatahichegeni 2026). Using 0.52 gives estimated volumes of 4.84 mL and 2.18 mL, respectively. In this calculator’s adult reference comparison, both estimates are below the ESUR-SPIWG 2025 hypotrophy limits (left 11 mL, right 12 mL). The authors described bilateral testicular hypoplasia with reduced testicular volume but did not report numerical volumes. The dimensions are retained in their published order because the axes were not specified.
| Item | Value |
|---|---|
| Right testis: Dimension 1 | 23 mm |
| Right testis: Dimension 2 | 14 mm |
| Right testis: Dimension 3 | 13 mm |
| Left testis: Dimension 1 | 31 mm |
| Left testis: Dimension 2 | 20 mm |
| Left testis: Dimension 3 | 15 mm |
| Right testis | 2.18 mL |
| Left testis | 4.84 mL |
| Formula | Ellipsoid (0.52) |
Radikulus convention: comparison offered for any adult. ESUR-SPIWG 2025 states these limits for male infertility evaluation; they derive from 248 healthy, fertile men aged 23–53 and use 0.52 volumes only. These sources do not validate the comparison in every adult population.
Volume alone does not establish fertility.
Frequently asked questions
How is testicular volume calculated on ultrasound?
This calculator uses 0.52 × length × width × height for each testis, or Lambert’s 0.71 × L × W × H. See How the volume is calculated.
What testicular volume indicates hypotrophy?
For adult male infertility evaluation, ESUR-SPIWG 2025 identifies right volume <12 mL or left <11 mL using the 0.52 ellipsoid formula. See Hypotrophy limits.
What is the Lambert formula for testicular volume?
0.71 × length × width × height. See How the volume is calculated and Accuracy.
Do the limits apply to boys and adolescents?
This calculator does not apply these adult limits under 18. The EAA reference cohort was aged 23–53; eligibility began at 18. See Hypotrophy limits.
References
- Lotti F, Studniarek M, Balasa C, et al. The role of the radiologist in the evaluation of male infertility: recommendations of the European Society of Urogenital Radiology-Scrotal and Penile Imaging Working Group (ESUR-SPIWG) for scrotal imaging. Eur Radiol. 2025;35(2):752-766. doi:10.1007/s00330-024-10964-5. PMID 39083089. (ESUR-SPIWG 2025)
- Lotti F, Frizza F, Balercia G, et al. The European Academy of Andrology (EAA) ultrasound study on healthy, fertile men: Scrotal ultrasound reference ranges and associations with clinical, seminal, and biochemical characteristics. Andrology. 2021;9(2):559-576. doi:10.1111/andr.12951. PMID 33244893.
- ACR–AIUM–SPR–SRU Practice Parameter for the Performance of Scrotal Ultrasound Examinations, revised 2025. https://gravitas.acr.org/PPTS/DownloadPreviewDocument?DocId=99
- AIUM Practice Parameter for the Performance of Scrotal Ultrasound Examinations, 2025 Revision. J Ultrasound Med. 2026;45(5):E10–E15. doi:10.1002/jum.70127.
- Sakamoto H, Saito K, Oohta M, Inoue K, Ogawa Y, Yoshida H. Testicular volume measurement: comparison of ultrasonography, orchidometry, and water displacement. Urology. 2007;69(1):152-157. doi:10.1016/j.urology.2006.09.012. PMID 17270639. Abstract-based review.
- Fatahichegeni M, et al. Atypical endocrine manifestations in Gordon syndrome caused by CUL3 mutation: a case report. Front Med (Lausanne). 2026;13:1862901. doi:10.3389/fmed.2026.1862901. PMID 42548885.
- Sholan R, et al. Preserving Fertility After Bilateral Testicular Gunshot Injury: A Case Report. Case Rep Surg. 2026;2026:1140740. doi:10.1155/cris/1140740.