CalculatorCentral.uk

Blood Pressure Calculator

Enter your values below to get the result first, then scroll for the full explanation and guidance.

Step 1 • Add values

Use the calculator

Enter your values below to generate an instant result. You can update the inputs at any time to compare different scenarios.

Example: 140/90 mmHg reaches the NICE clinic threshold; 135/85 mmHg reaches the home-average threshold.

Results refresh instantly as values change.

Single-reading threshold screen

Below high threshold128/82 mmHg

Single-reading threshold screen: Below high threshold (128/82 mmHg)

This compares one clinic reading with the applicable NICE high-blood-pressure threshold. It cannot diagnose hypertension.

Reading summary

This compares one clinic reading with the applicable NICE high-blood-pressure threshold. It cannot diagnose hypertension.

Result snapshot

A quick visual read of the values behind this result.

Systolic128 mmHg
Diastolic82 mmHg
Measurement contextClinic threshold: 140/90

Recommended next checks

  • →A clinic reading at or above 140/90 should be repeated and normally confirmed with ambulatory or home monitoring.
  • →For a reading at or above 180/120, follow urgent NHS clinical advice, especially if symptoms are present.
Systolic
128 mmHg
Diastolic
82 mmHg
Measurement context
Clinic threshold: 140/90

Try different values to compare results.

Choose whether the reading was taken in a clinic or at home, then enter systolic and diastolic pressure. The result is a threshold comparison for one adult reading, not a diagnosis or treatment recommendation.

Fast to use

Built for comparison

Clear result output

Table of Contents

5

About Blood Pressure Calculator

Blood Pressure Calculator helps you work through the main numbers for this topic quickly with a simple input flow and an instant result.

Use the calculator result as a practical starting point, then review the explanation and assumptions on the page if you want more context.

Why one reading is not a diagnosis

NICE uses 140/90 mmHg as the clinic threshold and an average of 135/85 mmHg for ambulatory or home confirmation. A raised clinic reading should be repeated and normally confirmed outside the clinic.

For home monitoring, NICE recommends twice-daily readings for at least 4 days, ideally 7, discarding day 1 and averaging the remainder. Readings at or above 180/120 need prompt clinical handling under NICE guidance, especially with concerning symptoms.

Formula explained

Calculation flow

This calculator is structured for fast UK-focused estimates with clear inputs, repeatable logic, and instant results.

Formula

Input values -> calculation engine -> instant result

How the result is built

1Enter the values requested in the form.
2The calculator applies the configured formula logic.
3The result updates instantly with a breakdown.
4Use the output to compare scenarios quickly.

Example

Example: 140/90 mmHg reaches the NICE clinic threshold; 135/85 mmHg reaches the home-average threshold.

Assumptions

  • Adult threshold screen only: clinic 140/90 mmHg; home average 135/85 mmHg; very high reading flag at 180/120 mmHg.
  • Systolic and diastolic values must be whole numbers and systolic must be higher than diastolic.
  • One reading cannot diagnose hypertension. Pregnancy, under-18s, symptoms, treatment decisions and individual clinical targets are outside scope.

Source basis

  • UK-focused calculator flow
  • Structured input validation
  • Instant result breakdowns

Trust and notes

Assumptions and important notes

This calculator is designed to give a fast estimate using the method shown on the page. Results are most useful when your inputs are accurate and the tool matches your situation.

Use the result as guidance rather than a final diagnosis or professional decision. If the result could affect health, legal, financial, or compliance decisions, verify it with a qualified source where appropriate.

  • Adult threshold screen only: clinic 140/90 mmHg; home average 135/85 mmHg; very high reading flag at 180/120 mmHg.
  • Systolic and diastolic values must be whole numbers and systolic must be higher than diastolic.
  • One reading cannot diagnose hypertension. Pregnancy, under-18s, symptoms, treatment decisions and individual clinical targets are outside scope.

Method

UK calculator guidance

Last reviewed

April 17, 2026