Bishop Score Calculator — Cervical Ripeness for Labour Induction
The Bishop score is the standard pre-labour cervical assessment used to predict whether a labour induction is likely to succeed. Score each of the five criteria (dilation, effacement, station, consistency, position) to get a total out of 13, with interpretation.
Cervical dilation
Cervical effacement
Fetal head station
Cervical consistency
Cervical position
Total score: 0 (least favorable) to 13 (most favorable)
- 1
Structural factors (dilation + effacement + station)
1 + 1 + 1 = 3 - 2
Soft-tissue factors (consistency + position)
1 + 1 = 2 - 3
Bishop score
3 + 2 = 5
How does this calculator work?
Bishop score = Dilation (0–3) + Effacement (0–3) + Station (0–3) + Consistency (0–2) + Position (0–2); maximum 13. Score ≥8: favorable, induction likely to succeed. Score ≤5: unfavorable, consider cervical ripening first. Score 6–7: intermediate. Developed by Edward Bishop in 1964.
Formula
How this is calculated
The Bishop score was introduced by obstetrician Edward Bishop in 1964 as a standardised method for quantifying cervical readiness for labour induction via digital pelvic examination. Five criteria are each scored and summed: cervical dilation (how wide the os is open: closed = 0, ≥5 cm = 3), effacement (how thin/shortened the cervix is: 0–30% = 0, ≥80% = 3), fetal head station relative to the ischial spines (−3 = 0, +1/+2 = 3), cervical consistency (firm = 0, soft = 2), and cervical position (posterior = 0, anterior = 2). The maximum total is 13.
The five criteria together reflect progressive cervical ripening that naturally precedes labour. Dilation and effacement indicate structural opening and shortening; station reflects descent of the fetal presenting part; consistency tracks biochemical softening of the cervical stroma; position reflects rotation of the cervix from posterior (towards the sacrum) to anterior (towards the pubic symphysis). All five shift in the final weeks of a term pregnancy as the cervix prepares for labour.
Interpretation thresholds: a score of 8 or above indicates a favourable cervix and is associated with a high rate of successful induction without prior pharmacological ripening. Scores of 6–7 are intermediate. Scores of 5 or below indicate an unfavourable cervix; cervical ripening agents (prostaglandins, misoprostol) or mechanical methods (balloon catheter) are typically considered before or alongside oxytocin induction. The score is one clinical input and must be interpreted alongside gestational age, the indication for induction, maternal and fetal well-being, and institution-specific protocols.
Frequently asked questions
A score of 8 or above is widely regarded as favorable, indicating a ripe cervix and a high likelihood of successful induction without additional cervical preparation. Some guidelines use a threshold of ≥6. Scores ≤5 indicate an unfavorable cervix; pre-induction ripening is generally recommended to shorten induction duration and reduce the risk of failed induction requiring caesarean section.
Dilation is the diameter of the cervical opening (os), from closed (0 cm) toward full dilation (10 cm in labour). Effacement is the thinning and shortening of the cervix, expressed as a percentage: 0% means fully thick and long (about 3–4 cm), 100% means completely thinned out. In nulliparous (first-time) labours, effacement typically precedes dilation; in multiparous labours both can occur simultaneously.
It was originally validated for induction success, not for predicting spontaneous labour onset. However, higher scores in late pregnancy correlate with closer proximity to spontaneous onset. A score above 8–9 at term often signals impending labour within days. Other factors — contraction pattern, membrane status, maternal history, and cervical position trend — are equally informative for timing predictions.
Also known as
TG we-Calculate Editorial Team. (2026). Bishop Score Calculator — Cervical Ripeness for Labour Induction [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/bishop-score-calculator
TG we-Calculate Editorial Team. "Bishop Score Calculator — Cervical Ripeness for Labour Induction." TG we-Calculate. 2026. https://we-calculate.com/calculator/bishop-score-calculator.
TG we-Calculate Editorial Team, "Bishop Score Calculator — Cervical Ripeness for Labour Induction," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/bishop-score-calculator
@misc{wecalculate_bishop_score_calculator, title = {Bishop Score Calculator — Cervical Ripeness for Labour Induction}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/bishop-score-calculator}}, year = {2026}, note = {TG we-Calculate} }
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