Content style guide - Numbers, measurements, dates and time

Content styles, including numerals, ordinals, dosage, temperature, fractions and percentages

Numbers

Numerals (1, 2, 3 and so on)

We use numerals for numbers (including 1 and 2), for example when we're talking about statistics, time, measurements, lists, points or steps. People find numerals easier to read and they scan for them.

For numbers over 999, use a comma for clarity - for example, 1,000.

For numbers less than 1, use 0 before the decimal point - for example, 0.25.

Examples
  • Add 1 to 2 teaspoons of honey.
  • Do this for 1 or 2 minutes.
  • It takes 1 to 3 weeks from the time you were exposed to chickenpox for the spots to start appearing.
  • Depression affects about 1 in 10 people at some point during their life.

Using numerals at the start of a sentence

It is OK to use numerals at the start of a sentence but, if it looks confusing, consider rewording your sentence.

Example

14 units is equivalent to 6 pints of average-strength beer or 10 small glasses of low-strength wine.

Using numerals in headings

It's also OK to use them in headings.

Examples
  • 8 tips for healthy eating
  • 6-in-1 vaccine

Using numerals in lists

You can use numerals in lists.

Examples

A portion is:

  • 80g of fresh, canned or frozen fruit and vegetables
  • 30g of dried fruit
  • 50ml glass of fruit juice or smoothie

Where we do not use numerals

One

We spell out "one" when it means "a" or to avoid repeating a word.

Example

Never take 2 doses at the same time to make up for a forgotten one.

We also use "one" in phrases like:

  • "one or the other"
  • "one of the most common"
  • "one at a time"
Dosage

We do not use numerals in some medicines information about dosage because we've found they can be confusing. Read more about numbers and dosage.

Ordinal numbers (1st, 2nd, 3rd and so on)

We use numerals with letter suffixes for ordinal numbers (including 1st and 2nd), for example, when we're talking about dates, quantities and things in a list or sequence.

Examples
  • a 2nd dose of vaccine
  • 2nd half of pregnancy
  • 3rd month of pregnancy
  • the 5th day of the month

We do not use ordinal numbers in phrases like:

  • first aid
  • first time
  • first visit
  • secondhand smoke
  • second opinion

Do not use superscript. It does not always read out correctly on screen readers and could confuse people.

Measurements

Calories

We use "calorie" when talking about calories in general, for example "calorie information on menus". Where appropriate, we explain that calories are often written as "kcal".

We use "kcal" as the unit of measurement. We do not put a space between the number and the measurement.

Example

The average man needs around 2,500kcal.

Dosage

We do not use a space between amount and measurement.

Example

The usual dose is 250mg to 500mg.

Use your judgement when explaining medicines doses. Avoid having 2 sets of numerals next to each other.

We say: We do not say:
The usual dose is one or two 200mg tablets 3 times a day. The usual dose is 1 or 2 200mg tablets 3 times a day.

Temperature

We use Celsius for temperature, but only when talking about children under 6 months old. For adults or children over 6 months old, we do not give a specific temperature.

Example

If your child is under 3 months old and has a temperature of 38C or higher, or you think they have a high temperature

Read more about temperature in the A to Z of NHS health writing.

Metric and imperial

We generally use metric. If it's helpful, add imperial in brackets, for example, for advice on cutting back on alcohol.

Do not use imperial for medicines dosage or infant feeding.

Dates

We use this format: 6 August 2018.

As far as possible, spell out months in full. Screen readers read out shortened months (Jan, Feb and so on) in inconsistent and sometimes confusing ways.

Time

TBD
We use: We do not use:
5.30pm 1730hrs
midnight 00:00, 12am
midday 12 noon, 12pm
6 hours 30 minutes 6.5hrs

Ranges of numbers, dates and time

We use "to" for time, date and numerical ranges, not hyphens or dashes.

Examples
  • The surgery is open Monday to Friday, 2pm to 6pm.
  • A BMI of 18.5 to 24.9 means you're a healthy weight.

Fractions and percentages

Spell out common fractions like two-thirds.

For percentages, use the % symbol - for example, 50%. However, it's often better not to use a percentage. Instead of 50%, for example, you could say "1 in 2" or "half".

Statistics

Use statistics sparingly. Consider the style of writing and your target audience. For example, readers of Behind the Headlines, the Health A to Z and Live Well on the NHS website will have different needs.

Use the clearest, most meaningful format to explain what you're illustrating. For example, use "1 in 7 people" rather than "14.3% of people".

Avoid mixing different number formats. Use one or the other.

Example

Overall, around 7 in every 10 people live at least a year after diagnosis and around 5 in 10 people live at least 10 years.

Get in touch

If you’ve got a question about the NHS digital service manual or want to feedback, you can contact the team:

Help improve the service manual

We’d welcome your feedback. Can you answer some questions about your visit today?

Updated: March 2020