Constant-Currency Growth: Why Rupee and Dollar Growth Differ

Constant-currency growth compares revenue while holding exchange rates fixed, so currency translation does not masquerade as business growth. It is useful when an Indian IT company reports different growth rates in rupees, US dollars and constant currency, but it is not a substitute for the financial statements.

Think of exchange rates as a changing measuring ruler. The business may deliver less work, yet its revenue can look larger when translated into rupees. Alternatively, customer-currency revenue can grow while an unfavourable translation movement reduces reported dollar growth.

The first question is therefore not which growth rate looks best. It is what each one measures.

Three growth rates, three questions

Measure	The question it helps answer	The important limit
Reported rupee growth	How did revenue in the rupee statements change?	Includes translation and business-scope effects
Reported dollar growth	How did the dollar presentation change?	Still affected by movements in other customer currencies
Constant-currency growth	How did revenue change with exchange rates held fixed?	May still include acquisitions and changes in business mix

A business serving customers in euros, pounds and dollars has more than one exchange rate to consider. Dollar reporting does not make it currency-neutral.

For a company-defined example of the method, Infosys’s FY2021 Form 20-F, under its revenue discussion, explains translating current-period local-currency revenue at prior-period exchange rates. This is a historical definition reference, not a claim about the latest quarter or a universal formula used by all issuers.

A worked example: revenue grows, but the business shrinks

The following is entirely hypothetical. It describes a simplified company billing only in US dollars, with one average exchange rate in each period. No figures are observations about a listed company or current exchange rates.

Input	Earlier period	Later period
Dollar revenue	$100 million	$98 million
Average translation rate	₹80 per dollar	₹88 per dollar
Reported rupee revenue	₹8,000 million	₹8,624 million

Reported rupee growth is ₹8,624 million divided by ₹8,000 million, minus one: 7.8%.

But dollar revenue fell from $100 million to $98 million: a 2% decline. Translating both periods at the earlier rate leaves the same 2% decline. In this deliberately simple example, that is constant-currency growth.

Both results can be correct. The company earned fewer dollars, while each dollar translated into more rupees.

The exact bridge is multiplicative: 0.98 × 1.10 = 1.078. Adding a negative 2% business movement to a positive 10% currency movement would give 8%, not the correct 7.8%, because it misses their interaction.

That difference is small here. It can matter when reconciling a model, particularly across several currencies or large movements.

Constant currency is not constant everything

Removing translation does not remove price increases, changes in services, acquisitions or contract timing. A company can post positive constant-currency growth after buying a business even when its original operations are not growing.

Ask whether management means reported constant-currency growth, organic constant-currency growth or a measure excluding a particular business. Preserve the exact label rather than treating them as interchangeable.

Nor does constant-currency revenue establish profitability. Employee costs, subcontracting, overseas delivery expenses and hedging can respond differently to currency. A revenue translation benefit is not automatically an equal improvement in operating profit or cash.

For those questions, put the revenue bridge beside the margin bridge and cash-flow statement. Our IT-services results framework covers those additional checks.

How to compare two IT results without mixing rulers

Start with the same comparison period. A sequential change from the preceding quarter is not comparable with growth over the corresponding quarter a year earlier. Seasonality and the base can change the interpretation even before currency enters the calculation.

Then record the reporting scope and the issuer’s constant-currency method. Note acquisitions, disposals and whether a software business is included. A more favourable number does not justify changing the basis midway through the comparison.

Finally, retain the disclosed reconciliation. A quarter-end USD/INR rate is not a shortcut to a multi-currency revenue calculation earned throughout the period. If the published information does not let you reproduce the adjustment, preserve that limitation instead of forcing an unexplained residual to zero.

The company-comparison checklist provides a blank evidence worksheet for those period and scope checks.

What belongs in the research model

Keep reported actuals as reported. Use a separate, labelled view for currency-neutral analysis and explicit exchange-rate assumptions for forecasts. Otherwise, a future reader cannot tell whether a changed revenue estimate reflects demand, currency or both.

Write a short review note: the source, period, reported growth, constant-currency growth, acquisition scope and the remaining unexplained difference. Add what evidence would change your interpretation next quarter. That is more useful than copying the most flattering headline into the model.

Altys’s research approach emphasizes source-linked evidence, reusable research and reviewable outputs. Request access with a company and a real comparison task to evaluate that workflow. Analysts remain responsible for checking definitions, assumptions and conclusions; AI does not make mismatched periods comparable.

For the wider context, read how USD/INR affects portfolio exposures and the revenue-growth bridge. This article explains measurement, not a currency forecast or an investment call.