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Quick answer — beta-hCG to weeks pregnant (LMP)
1,500 mIU/mL usually maps to about 5–6 weeks LMP (3–4 weeks from conception) — typical band 500–6,000 mIU/mL. 6,000 mIU/mL → 6–7 weeks LMP. Ranges overlap widely; early pregnancy needs serial hCG (often ≥53% rise in 48 h) and ultrasound for dating and location.
Enter quantitative beta-hCG to estimate how many weeks pregnant on an LMP teaching scale, with hCG levels by week and doubling-time guidance. More on our Medical & Health hub.
Last updated October 9, 2026
Educational only—not medical advice. One beta-hCG level cannot confirm viability or rule out ectopic pregnancy.
Quantitative blood test result
Estimated gestational age (LMP)
5–6 weeks LMP
Teaching band from beta-hCG 1,500 mIU/mL
From conception
3–4 weeks from conception
Trimester
First trimester
Typical range for this band
500–6,000 mIU/mL
Expected doubling time (teaching)
72–96 hours
Interpretation
Includes common values like 1,500 mIU/mL. Intrauterine gestational sac often seen on transvaginal ultrasound around 5 weeks LMP.
Not for diagnosis. Ultrasound and serial beta-hCG with your clinician when symptoms or fertility treatment warrant.
Same logic as the calculator—illustrative bands, not exact dating.
| Scenario | Level | Weeks LMP (band) | From conception | Doubling (teaching) |
|---|---|---|---|---|
| Below detection — 4 mIU/mL | 4 mIU/mL | Not pregnant or below threshold | Below typical detection | N/A |
| Very early — 25 mIU/mL | 25 mIU/mL | 3–4 weeks LMP | 1–2 weeks from conception | 48–72 hours |
| Early — 120 mIU/mL | 120 mIU/mL | 4–5 weeks LMP | 2–3 weeks from conception | 48–72 hours |
| Default — 1,500 mIU/mL | 1,500 mIU/mL | 5–6 weeks LMP | 3–4 weeks from conception | 72–96 hours |
| Common level — 6,000 mIU/mL | 6,000 mIU/mL | 6–7 weeks LMP | 4–5 weeks from conception | 96+ hours |
| Late first trimester — 85,000 mIU/mL | 85,000 mIU/mL | 7–10 weeks LMP | 5–8 weeks from conception | 96+ hours (slowing) |
5–6 weeks LMP
72–96 hours
4–5 weeks LMP
6–7 weeks LMP
7–10 weeks LMP
Doubling example: 800 → 1,680 mIU/mL in 48 h ≈ 45 hour doubling time (teaching).
| Weeks LMP | From conception | hCG (mIU/mL) | Doubling (teaching) | Milestone |
|---|---|---|---|---|
| 3–4 | 1–2 wks | 5–50 | 48–72 h | Often just detectable; repeat in 48–72 h |
| 4–5 | 2–3 wks | 50–500 | 48–72 h | Early intrauterine pregnancy possible on US |
| 5–6 | 3–4 wks | 500–6,000 | 72–96 h | Gestational sac often visible ~5 wks LMP |
| 6–7 | 4–5 wks | 6,000–20,000 | 96+ h | Yolk sac / heartbeat era on TV US |
| 7–10 | 5–8 wks | 20,000–100,000 | Slowing | Rapid rise toward first-trimester peak |
| 10–12 | 8–10 wks | 100,000–200,000+ | Plateau | Peak then decline begins |
| Beta-hCG level | Expected pattern |
|---|---|
| < 1,200 mIU/mL | Double every 48–72 hours (minimum ~53% rise in 48 h) |
| 1,200 – 6,000 mIU/mL | Double every 72–96 hours |
| > 6,000 mIU/mL | Doubling slows; plateau near 10–12 weeks LMP |
Doubling time (hours) ≈ (hours between tests × 0.693) ÷ ln(second ÷ first)
Minimum viable rise often cited: ≥53% in 48 hours when still early.
| Pattern | Rule of thumb | Clinical meaning (summary) |
|---|---|---|
| Appropriate rise | ≥53% increase in 48 h (often doubles in 48–72 h when <1,200 mIU/mL) | Compatible with intrauterine viable pregnancy in many cohorts—still needs clinical correlation |
| Slow rise | <53% in 48 h or plateau | Ectopic pregnancy, miscarriage, or wrong dates until ultrasound clarifies |
| Falling | Decline between serial draws | Completed or impending loss, or resolving ectopic—urgent obstetric review |
| Very high for dates | Markedly above median for assumed week | Consider multiples, molar pregnancy, or overstated gestational age—ultrasound key |
Useful when ultrasound is not yet due and you need a rough “how many weeks” context. Pair with serial rise and symptoms review.
Confirms intrauterine pregnancy and beats hCG for precise dating. If LMP is reliable, also try our gestational age calculator.
Ectopic pregnancy emergency: severe abdominal pain, shoulder pain, dizziness, or heavy bleeding with positive pregnancy tests need immediate obstetric or emergency care—not this calculator.
For early pregnancy, fertility communities, and nursing education
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