GDP Growth Rate Calculator
From current and previous GDP, compute the growth rate: (current − previous) ÷ previous × 100%, measuring expansion or contraction between two periods.
Input Data
Results
At a glance:GDP growth rate = (current GDP − previous GDP) ÷ previous GDP × 100% — the expansion or contraction between two periods, the most direct business-cycle gauge. Positive = expansion, negative = contraction (two straight quarters of negative real GDP is a technical recession). To reflect true growth, use real GDP (inflation-adjusted); nominal GDP also embeds inflation and overstates real growth. Mind base effects and seasonality (quarterly data is seasonally adjusted). The choice of periods sets whether it is q-on-q or y-on-y.
Formula
GDP growth rate = (current GDP − previous GDP) ÷ previous GDP × 100%.
$$g = \dfrac{\text{GDP}_{t} - \text{GDP}_{t-1}}{\text{GDP}_{t-1}} \times 100\%$$How to Use
- Enter current GDP (newer period; prefer real GDP).
- Enter previous GDP (older period).
- View the growth rate.
GDP growth examples (HK$100M)
| Scenario | Current GDP | Previous GDP | Change | Growth |
|---|---|---|---|---|
| Expansion | 15,000 | 14,300 | +700 | +4.90% |
| Mild expansion | 13,636.36 | 13,000 | +636.36 | +4.90% |
| Contraction | 14,000 | 14,500 | −500 | −3.45% |
Positive = expansion, negative = contraction. Use real GDP in both periods, else inflation inflates the figure.
Case Studies
Case 1: Annual GDP growth
Current (this year) real GDP = 15,000; previous (last year) real GDP = 14,300.
Growth = (15,000 − 14,300) ÷ 14,300 × 100% ≈ 4.90%.
Positive 4.90% means real expansion of ~4.9%. Using real GDP in both periods, this reflects true output gain, not prices — a valid business-cycle gauge.
Case 2: Negative growth and contraction
Real GDP current = 14,000, previous = 14,500 → growth = (14,000 − 14,500) ÷ 14,500 × 100% ≈ −3.45%.
Negative means ~3.45% contraction vs prior. If this is seasonally adjusted q-on-q and next quarter is also negative, it forms 'two straight negative quarters' — the usual technical-recession warning.
Note: a single negative quarter is not necessarily a recession (data wobble); confirm with employment, consumption, industrial output, and whether it is q-on-q or y-on-y.
FAQ
Use nominal or real GDP for growth?
Use real GDP (inflation-adjusted). Nominal GDP at current prices mixes two things: real output change and price change. Using nominal growth counts pure price rises as 'growth', overstating it. Extreme case: same output, prices +5% → nominal shows +5% but real growth is 0. Only real GDP (fixed base prices) strips prices to show true output growth. Official 'economic growth' is almost always real GDP. Enter real GDP in both periods for true expansion; nominal gives nominal growth (includes inflation) — note the difference. Convert via the GDP deflator.
What is a technical recession; is negative growth a recession?
A technical recession is the rule of thumb: two consecutive quarters of negative real GDP (q-on-q contraction). Simple and quick, so media/markets use it. But a single negative quarter is not a recession — data wobble; only two straight quarters signal a real downturn. Also distinguish q-on-q (vs prior quarter, seasonally adjusted) from y-on-y (vs same quarter last year). Strictly, bodies like the US NBER also weigh employment, industrial production, income and consumption, not just two quarters of GDP — sometimes GDP dips but jobs/consumption stay strong, not formally a recession. So 'two straight negative quarters' is a handy early warning, but judge with more indicators.
Quarter-on-quarter vs year-on-year growth?
They differ by which period you compare, each with use. Q-on-q compares the current quarter with the immediately prior one — captures the latest short-term momentum, sensitive to turning points, but prone to seasonality (year-end retail peaks, harvest cycles), so usually seasonally adjusted. Y-on-y compares with the same quarter last year — naturally avoids seasonality, smoother, better for long-term trend, but slower to react and subject to base effects (an unusually high/low prior-year base distorts this year's figure). Practice: use seasonally adjusted q-on-q for short-term turns, y-on-y for trend and cross-year compare. In this calculator, whichever two periods you enter is what the rate covers — adjacent periods = q-on-q, same quarter a year apart = y-on-y.
How to get CAGR from growth rates?
To know 'long-run average annual growth' rather than one year's swing, use CAGR — it smooths cumulative growth into a steady annual rate. This calculator gives single-period growth; CAGR converts 'start to end across years' into an assumed constant compound rate: CAGR = (end ÷ start)^(1 ÷ years) − 1. Example: real GDP 12,000 five years ago, 15,000 now → CAGR = (15,000 ÷ 12,000)^(1÷5) − 1 = 1.25^0.2 − 1 ≈ 4.56%. Note CAGR differs from the arithmetic mean of yearly rates — it accounts for compounding, usually a bit lower, and better reflects cumulative growth. Use CAGR for long-term trend, single-period for recent momentum. Pair with the CAGR calculator.
Can the Rule of 72 apply to GDP growth?
Yes — a handy mental shortcut. The Rule of 72 estimates doubling time at a fixed compound rate; applied to GDP: doubling years ≈ 72 ÷ growth rate (%). Example: steady real growth 4.9% → 72 ÷ 4.9 ≈ 14.7 years to double the economy; at 6% → 12 years; at 2% → 36 years. It vividly shows 'small rate differences mean huge gaps long term' — raising growth from 2% to 4% halves doubling time (36→18 years). The rule is approximate (best at 6%–10%); real growth varies yearly, so use it for compounding intuition, not precise prediction. Pair with the rule-of-72 calculator.
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References
Content review: Calculatorism Finance Team. Results are for reference only; please refer to the relevant authorities for the official figures.