Bishop Score Calculator

Introduction

A Bishop score is the number an OB uses to decide whether an induction will work. It comes from a vaginal exam that rates five things: how open the cervix is, how thin it feels, where the baby’s head sits relative to the ischial spines, how firm the cervix is, and which direction it points. Add those five subscores together and you get a value between 0 and 13.

This calculator handles that addition. It helps if you’re reading your own chart and wondering what “Bishop 4” means. It also helps student midwives, doulas, and nurses learning to score cervical exams accurately. Enter the five findings, and the tool returns your total plus the clinical category. No account, no upload, no data stored anywhere. Everything runs in the browser.

How to Use the Bishop Score Calculator

1. Pick a preset if you want a known starting point. Five built-in examples span the range from fully unfavorable to very favorable.

2. Set dilation from the dropdown. Choices run from closed to 5 cm or more.

3. Choose effacement. The scale goes in 10% bands, from 0–30% up to 80% or more.

4. Select fetal station. Options are −3, −2, −1 or 0, and +1 or +2.

5. Pick cervical consistency: firm, medium, or soft.

6. Choose position: posterior, midposition, or anterior.

7. Read the hero score. It shows your total out of 13 and updates as you change any dropdown.

8. Check the score bar below the tiles. The marker slides along a green-yellow-red track so you can see where you sit.

How the Bishop Score Calculator Formula Works

The Bishop score is a sum, not a weighted formula. Each of the five components contributes its own subscore and nothing is multiplied or divided.

Formula: Bishop Score = Dilation + Effacement + Station + Consistency + Position

Three components (dilation, effacement, station) score 0–3. Two (consistency, position) score 0–2. The maximum possible total is 13.

The scoring bands are clinical convention, not arithmetic:

• Dilation: closed = 0, 1–2 cm = 1, 3–4 cm = 2, ≥5 cm = 3

• Effacement: 0–30% = 0, 40–50% = 1, 60–70% = 2, ≥80% = 3

• Station: −3 = 0, −2 = 1, −1 or 0 = 2, +1 or +2 = 3

• Consistency: firm = 0, medium = 1, soft = 2

• Position: posterior = 0, midposition = 1, anterior = 2

No validation errors are possible because every dropdown only offers valid inputs. Change any component and the total updates instantly.

Worked Example: A 7-Point Borderline Exam

Suppose a first-time mother at 39 weeks has the following exam findings. Dilation 1–2 cm (1 point). Effacement 60–70% (2 points). Station −1/0 (2 points). Consistency medium (1 point). Position midposition (1 point).

Add those up and the score is 7. That sits right on the border between unfavorable and favorable. The calculator flags it as Borderline, induction may be attempted, but ripening is often preferred.

Now change one finding. If the cervix has rotated forward from mid to anterior, position bumps from 1 point to 2. The total becomes 8. That’s a Favorable score, and the expected success rate for induction jumps above 90%. One exam finding, flipped. That’s why the score gets rechecked right before induction rather than two days earlier.

A different scenario: same patient, but dilation is closed (0 points) and effacement is 0–30% (0 points). Score drops to 4. Unfavorable. The clinical team would likely recommend prostaglandins, a Foley balloon, or laminaria before starting oxytocin.

Understanding the Bishop Score:

The Bishop score is older than most of the drugs used to induce labor. Edward Bishop published it in 1964, and it stuck because it’s simple and it works. Every OB, midwife, and family medicine resident in the U.S. still uses it. The score predicts two things: how likely induction is to succeed, and how likely a cesarean will be needed if induction is attempted.

What Is a Bishop Score?

A Bishop score is a 0–13 rating of cervical readiness for labor induction. It combines five exam findings: dilation, effacement, fetal station, consistency, and position. Higher scores mean a softer, more open, more forward cervix, which is what oxytocin needs to work. The score doesn’t measure contractions or the baby’s size. It only rates the cervix itself.

What Is a Favorable Bishop Score?

A score of 8 or higher is considered favorable. Some guidelines treat 7 as borderline. Below 6, most clinicians recommend ripening before induction. A favorable score means induction with oxytocin alone is likely to succeed, with a cesarean rate close to what you’d see in spontaneous labor.

How Do You Calculate the Bishop Score Manually?

Add the five component subscores together. Dilation and effacement and station each give 0–3. Consistency and position each give 0–2. That’s the whole formula. The tricky part isn’t the arithmetic; it’s assigning the subscores correctly during the exam. Consistency is the most subjective of the five.

What Does a Bishop Score of 5 Mean?

A score of 5 lands in the unfavorable range. Induction is unlikely to succeed without ripening. Most U.S. guidelines recommend cervical ripening for any score below 7. Score 5 specifically means the cervix is firm and mostly closed, the baby’s head is still high, and the cervix hasn’t rotated forward. Prostaglandins or a mechanical ripening method usually comes next.

Why Is My Bishop Score Low?

A low score usually just means the cervix hasn’t started preparing for labor yet. It’s normal at 37 or 38 weeks in a first pregnancy. It becomes a clinical concern only when induction is needed for a medical reason and the cervix isn’t cooperating. If your provider says your score is low, it’s not a diagnosis. It’s a forecast about how the next 12–24 hours of induction are likely to go.

When Is Cervical Ripening Needed?

Cervical ripening is recommended when the Bishop score is less than 7. At that point the cervix is too firm or too closed for oxytocin to work well. Ripening methods include misoprostol (Cytotec), dinoprostone (Cervidil, Prepidil), a transcervical Foley balloon, and laminaria. Which one gets used depends on the clinical situation, prior cesarean history, and hospital protocol.

What Is the Modified Bishop Score?

The modified Bishop score drops station and adds cervical length measured by ultrasound. It’s used in some European centers because ultrasound gives a more objective measurement than digital exam. The original score is still the standard in U.S. practice. For most inductions, the classic five-component version is what your provider will use.

Does a High Bishop Score Mean Labor Is Close?

Not necessarily. A high score means the cervix is ready if labor is induced. It doesn’t predict when spontaneous labor will start. Plenty of women walk around at 39 weeks with a Bishop score of 8 and no contractions for another week. The score is a snapshot of readiness, not a countdown.

Common Mistakes When Scoring the Cervix

Two come up often. First, confusing effacement percentages at the extremes, the difference between “70%” and “80%” is one point and it matters. Second, under-scoring a cervix that has rotated forward. An anterior cervix that feels only “medium” might still be marked as posterior if the examiner isn’t careful. Re-examining when the score seems inconsistent with the clinical picture is standard practice.

Benefits of Using This Bishop Score Calculator

• You get the category, not just the number. The tool converts your total into Unfavorable, Borderline, or Favorable and tells you what that means clinically.

• The score bar shows context. A marker slides along a color-coded 0–13 track so you can see the boundary at a glance instead of counting points in your head.

• Presets cover the standard cases. Five examples from a fully unfavorable cervix to a very favorable multiparous exam let you compare patterns side by side.

• Subscores stay visible. Each of the five tiles shows both the point value and the raw finding (like “60–70%” or “−2”), so you can double-check your inputs.

• No data leaves your device. Every calculation runs in JavaScript in your browser. Nothing is sent to a server, so patient data stays private.

• Works on a phone at the bedside. The dropdowns are touch-friendly, the layout collapses cleanly, and the score updates as you tap through findings.

Frequently Asked Questions

What is a normal Bishop score?

There’s no “normal” score. A cervix at 38 weeks in a first pregnancy typically scores 2 to 5. The same cervix at 40 weeks in a third pregnancy often scores 8 or higher. The score describes readiness for induction, not health. A low score isn’t abnormal — it just means the cervix hasn’t started its pre-labor changes yet.

What is a favorable Bishop score for induction?

A score of 8 or higher. At that threshold, induction with oxytocin alone has a success rate above 90% and a cesarean rate similar to spontaneous labor. Scores of 6 to 7 sit in a gray zone where ripening often improves outcomes. Below 6, most guidelines recommend ripening before induction.

What happens if my Bishop score is low?

Your provider will likely recommend cervical ripening first. That can mean a prostaglandin medication, a Foley balloon, or laminaria. Ripening softens and opens the cervix over 12 to 24 hours. Once the score improves, oxytocin induction usually proceeds. A low score doesn’t mean induction is impossible. It just means the cervix needs help first.

Is a Bishop score of 10 good for induction?

Yes. A score of 10 means dilation, effacement, and station are all high, plus a soft and forward cervix. That’s the most favorable pattern short of full active labor. Induction at that point is very likely to succeed with oxytocin alone and without ripening.

When is the Bishop score checked?

Typically at the start of induction. Some providers check it at a routine 39-week visit too, especially if an earlier induction might be needed. Because the cervix changes quickly in the days before labor, a score from 48 hours ago may not reflect what you have now. The score used for the actual induction decision gets taken right before the procedure.

Can the Bishop score predict how long induction will take?

Roughly. Favorable scores correlate with shorter inductions. A score of 8 or higher usually means 12 to 18 hours from the start of oxytocin to delivery in a first-time mother. Scores below 6 often mean a longer process, sometimes 24 hours or more, especially if ripening is needed first. The score predicts likelihood of success better than exact duration.

Does the Bishop score work for VBAC candidates?

Not as well. The score was validated in women without prior cesarean deliveries. For VBAC, the decision depends more on prior delivery history, the reason for the previous cesarean, and hospital policy than on the Bishop score. Your provider may still use it as one data point, but it isn’t the primary decision tool.

Is the Bishop score still used in modern obstetrics?

Yes. It’s been in continuous clinical use for over 60 years. Ultrasound-based cervical length has been added in some settings, and the modified Bishop score replaces station with cervical length in some European protocols. But the classic five-component score remains the standard in U.S. obstetrics because it’s fast, requires no equipment beyond a gloved hand, and has decades of outcome data behind it.

Can I calculate my own Bishop score at home?

No. All five components require a vaginal exam by a trained clinician. Dilation, effacement, station, consistency, and position can’t be self-assessed. This calculator is designed for people who’ve already been examined and want to understand their results, or for students learning the scoring system.