Bishop score calculator (cervical readiness for induction)

How this Bishop score calculator works

This Bishop score calculator adds the points for five findings on vaginal examination: cervical dilation, effacement, consistency and position, and the station of the presenting part. Edward Bishop described the system in Obstetrics and Gynecology in 1964 as a "pelvic score" for deciding when elective induction of labour was likely to succeed. Dilation, effacement and station score 0 to 3 points each, and consistency and position score 0 to 2, so the total runs from 0 to 13. Bishop built the score in multiparous women at term who had given birth vaginally before, using the induction methods of the early 1960s. The point table below is the one ACOG reprints from Bishop's paper in its 2025 guideline on cervical ripening. NICE NG207 lists the same five findings, with "effacement (or length)"; the cervical length version is covered in the guide to the modified Bishop score.

Worked example: a cervix 2 cm dilated, 50% effaced, at station −2, soft and mid-position scores 1 + 1 + 1 + 2 + 1 = 6, which is in the 6-or-less group NICE uses. A cervix 3 cm dilated, 70% effaced, at station −1, soft and anterior scores 2 + 2 + 2 + 2 + 2 = 10.

Bishop score results: what the guidelines say

The Bishop score has no single cut-off that every guideline shares, so this calculator shows the bands as each source states them. NICE guideline NG207 (Inducing labour, 2021) says a score of 8 or more generally indicates that the cervix is ready to dilate, the state once called "ripe" or "favourable", with a high chance of spontaneous labour or of response to induction. For its recommendations NICE splits women into a Bishop score of 6 or less and more than 6, and uses that split to help choose between groups of induction methods. ACOG Clinical Practice Guideline No. 9 (2025) says there is no universally accepted definition of an unfavourable cervix, and that cut-offs from 3 to 8 have been used in studies. Bishop himself reported that at 9 or more he had no failed inductions and an average labour of under 4 hours, in multiparous women at term. Parity and gestation also change the outlook.

When the Bishop score is less reliable

The Bishop score predicts the outcome of induction only modestly, so a single number should be read alongside the whole clinical picture. In a systematic review of 40 studies and 13,757 women induced at term, Kolkman and colleagues (American Journal of Perinatology, 2013) found the score a poor predictor of caesarean birth, and concluded that it should not be used to decide whether to induce labour. The score was derived in multiparous women at term having elective induction with the methods of the 1960s, while today it is used in first pregnancies, preterm births and medically indicated inductions, with outcomes now judged by birth within 24 hours. ACOG's 2025 guideline covers term, singleton, head-first pregnancies with intact membranes, and notes that parity and gestational age also affect how induction goes. In 5,610 nulliparous women (Laughon 2011), only dilation, station and effacement were significantly linked to vaginal birth. NICE advises reassessing the score at intervals during induction.