Fibroid Sizes Chart In Cm and Fibroids: What to Know

Uterine fibroids (leiomyomas) are common, noncancerous growths of the uterus that can range from microscopic to melon-sized. Understanding how fibroid size is measured—and what those measurements mean for symptoms, fertility, and treatment—can help you make informed decisions. Below is a practical size guide in centimeters (cm), plus evidence-based insights from trusted sources.

Quick fibroid sizes “chart” in centimeters

Clinicians often describe fibroids by their largest diameter. While there’s no universal “official” size chart, the ranges below are commonly used in practice to frame discussions:

• Very small: <1 cm (often incidental on ultrasound; may be asymptomatic)
• Small: 1–2 cm (about the size of a pea to a cherry)
• Medium: 2–5 cm (plum to small lemon); may cause bleeding if near the uterine lining
• Large: 5–10 cm (orange to grapefruit); more likely to cause “bulk” symptoms like pressure, urinary frequency, or bloating
• Very large: >10 cm (grapefruit to melon); can enlarge overall uterine size and significantly impact comfort or fertility

Doctors might also describe overall uterine size using “weeks” (e.g., “12-week uterus”) as a rough comparison to pregnancy size. This is a shorthand for the uterus’s total enlargement from fibroids, not a pregnancy measurement.

Size is only part of the story: location and number matter

Symptoms depend on the fibroid’s size, location, and number:

• Submucosal (inside the uterine cavity): Even small fibroids can cause heavy or prolonged menstrual bleeding and anemia, and may affect fertility.
• Intramural (within the uterine wall): Can cause heavy bleeding and cramping; larger sizes contribute to bulk symptoms.
• Subserosal (outer surface of the uterus): Less likely to cause bleeding; large ones may press on the bladder, bowel, or nerves.

Clinicians sometimes use the FIGO leiomyoma system to classify fibroids by location (submucosal, intramural, subserosal), which helps guide treatment choices.

How doctors measure fibroids

• Pelvic ultrasound: Most common. Reports list diameters in millimeters or centimeters. Growth is typically assessed over time.
• MRI: Provides detailed mapping of size, number, blood supply, and location—helpful for complex cases or pre-procedure planning.
• Volume estimates: Sometimes used (length × width × height × 0.52) to track total fibroid burden.
• Hysteroscopy: For submucosal fibroids, direct visualization helps determine how much protrudes into the cavity.

When does fibroid size matter?

• Symptoms: Larger fibroids are more likely to cause pressure symptoms, but small submucosal fibroids can cause significant bleeding.
• Fertility and pregnancy: Submucosal or large intramural fibroids that distort the cavity may reduce fertility or increase pregnancy risks (miscarriage, malpresentation). Location and distortion often matter more than raw size.
• Surgical approach: Very large uteri or fibroids may necessitate open rather than minimally invasive surgery. The U.S. FDA has issued specific cautions about certain surgical tools (power morcellators) due to rare risk of spreading undiagnosed cancer; discuss approach and alternatives with your surgeon.
• Monitoring: Rapid change in size can prompt re-evaluation, though size alone rarely distinguishes benign from malignant growths.

Do big fibroids mean cancer?

Uterine fibroids are benign. Uterine sarcoma (a different, malignant tumor) is rare. Size alone does not predict cancer. The U.S. Food and Drug Administration (FDA) estimates the risk of an unexpected uterine sarcoma in women undergoing surgery for presumed fibroids is on the order of approximately 1 in 225 to 1 in 580; earlier estimates were about 1 in 350. Preoperative tests cannot reliably rule out sarcoma. If you have concerning features (e.g., postmenopausal growth, atypical imaging, or unusual bleeding), your clinician may recommend additional evaluation.

Treatment options by goal and size

There is no one-size-fits-all approach. Your plan should reflect your symptoms, fibroid size and location, desire for future pregnancy, and medical history.

Watchful waiting

• Reasonable for small, asymptomatic fibroids. Periodic exams and imaging track changes.

Medications (symptom control; do not eliminate fibroids)

• NSAIDs for pain and cramps.
• Tranexamic acid during menses to reduce heavy bleeding.
• Hormonal methods (combined pills, progestin-only methods, levonorgestrel IUD) help manage bleeding.
• GnRH antagonists with add-back therapy (FDA-approved options include elagolix combination therapy and relugolix combination therapy) can significantly reduce heavy menstrual bleeding due to fibroids in premenopausal women.
• GnRH agonists (e.g., leuprolide) can shrink fibroids temporarily, often used preoperatively or near menopause because of side effects with longer use.

Uterus-sparing procedures

• Hysteroscopic myomectomy: Removes submucosal fibroids via the cervix; ideal for cavity-distorting fibroids generally up to a few centimeters depending on type and surgeon expertise.
• Laparoscopic or open myomectomy: Removes intramural or subserosal fibroids; approach depends on size/number/location and surgeon experience.
• Uterine artery embolization (UAE/UFE): Catheter-based procedure that blocks blood supply to fibroids, shrinking them and easing bleeding and bulk symptoms.
• Radiofrequency ablation: Laparoscopic or transcervical techniques heat and shrink fibroids; best for select sizes and locations.
• MRI-guided focused ultrasound: Noninvasive thermal ablation for carefully selected patients and fibroid characteristics.

Definitive treatment

• Hysterectomy: Removes the uterus; eliminates fibroids and bleeding. Route (vaginal, laparoscopic, open) depends on size, anatomy, and medical factors.

Note on surgical technique: The FDA advises against the use of power morcellation for many patients because of the risk of spreading an unsuspected uterine sarcoma. If morcellation is considered, the FDA recommends using it only in appropriately selected patients and with a tissue containment system. Discuss the pros and cons with your surgeon.

When to see a clinician

• Heavy or prolonged periods, passing clots, or anemia symptoms (fatigue, shortness of breath)
• Pelvic pressure, pain, urinary frequency/urgency, constipation, or back pain
• Difficulty getting or staying pregnant
• Rapidly changing abdominal size or new symptoms after menopause

Key takeaways

• “Small,” “medium,” and “large” fibroids are helpful shorthand; in cm, small is often 1–2 cm, medium 2–5 cm, large 5–10 cm, and very large >10 cm.
• Location often predicts symptoms more than size alone—especially for fibroids that distort the uterine cavity.
• Treatments range from watchful waiting to medications and minimally invasive procedures; choices should be tailored to your goals and health profile.
• Cancer is rare; size alone doesn’t indicate malignancy, but any concerning change warrants medical evaluation.

Trusted sources and further reading

• American College of Obstetricians and Gynecologists (ACOG) – Uterine Fibroids: ACOG FAQ
• U.S. National Institutes of Health (NIH), NICHD – Uterine Fibroids: NICHD overview
• MedlinePlus (NIH) – Uterine Fibroids: MedlinePlus
• U.S. Food and Drug Administration (FDA) – Laparoscopic Power Morcellators and Uterine Tissue: FDA safety communication
• FDA – Approved medicines for heavy menstrual bleeding due to fibroids (e.g., elagolix combination, relugolix combination): See product labeling via Drugs@FDA

This article is for general education and does not replace personalized medical advice. If you have symptoms or questions about fibroid size and treatment, consult a qualified clinician.