Gross domestic product

Reviewed 14 October 2026

Okenitemode explains how UK indicators are built and read. Nothing on this page is a forecast, a recommendation, or a substitute for the official statistical bulletin. Worked numbers below are invented so the arithmetic is visible. They are not Office for National Statistics figures.

What is being added up

Statisticians try not to count the same output twice. Flour sold to a bakery is an intermediate input. The loaf sold to a household is a final product. GDP is interested in the final product, or, equivalently, in the value added at each stage.

The Office for National Statistics estimates UK GDP in three ways that should, in principle, meet:

• Output. Value added by industries: services, production, construction, and agriculture. Services are the large share of the UK total.
• Expenditure. Household consumption, investment, government consumption and investment, plus exports, minus imports. Imports are subtracted because they were not produced here, even though a household may have bought them.
• Income. Compensation of employees, gross operating surplus, and taxes on production and products less subsidies.

Early in the quarter the three estimates do not match exactly. The ONS publishes a statistical discrepancy and later balances the accounts more fully. If a commentary treats a small gap between approaches as a mystery, it is usually just the timetable.

Prices and volumes

Nominal GDP, sometimes called GDP in current prices, uses the prices of the period itself. Real GDP, published as a chain-volume measure, strips out price change so that a rise means more volume of output, not merely higher price tags.

The GDP deflator is the bridge between them. It is a broad price index implied by the national accounts. It is not the Consumer Prices Index. CPI watches a household basket. The deflator watches the whole of domestic production, including investment goods and exports.

A worked sum that is not the UK

Imagine a toy economy that makes only loaves and chairs. In year one it sells 100 loaves at £2 and 10 chairs at £40. Nominal GDP is 200 plus 400, which is £600.

In year two it sells 110 loaves at £2.20 and 10 chairs at £44. Nominal GDP is 242 plus 440, which is £682. That is a 13.7 percent rise in money value.

Valued at year-one prices, year-two output is 110 times £2 plus 10 times £40, which is £620. Volume has risen by 3.3 percent. The rest of the nominal jump is price. The implied deflator has risen from 1 to 682 divided by 620, about 10 percent. None of these figures describes Britain. They only show why a current-price headline and a volume headline can diverge.

Monthly, quarterly, and the habit of revision

The ONS publishes a monthly GDP estimate and a fuller quarterly set of national accounts. Monthly figures are timely and noisy. Quarterly figures carry more detail and are still revised as annual surveys, tax data, and benchmark updates arrive. Blue Book updates can move history by more than the latest month did.

When you quote a growth rate, name three things: the series (monthly or quarterly), the comparison (month on previous month, three months on the previous three, or year on year), and whether it is a volume measure. “GDP rose” without those three is not yet a sentence.

What GDP refuses to be

• It is not median household income, and it is not the wage packet.
• Unpaid care and household production are mostly outside it.
• It does not subtract environmental damage unless a specific satellite account does so on purpose.
• Gross national income is a different concept: it follows income of UK residents, including some income earned abroad, rather than production on UK territory.
• Regional gross value added is not a miniature GDP print you can add up casually to the national total without watching the definitions.

Per-head GDP divides the total by population. A growing total can still leave output per person flat if the population has grown as fast. That comparison belongs in any honest conversation about “growth”.