Start with the reported movement
Take an illustrative group whose annual revenue rose from €100 million to €112 million. Its reconciliation attributes €7 million to an acquisition and €2 million to translating overseas sales into euros. That leaves €3 million of growth from existing operations measured at constant exchange rates. On last year’s base the three effects are seven, two and three percentage points. The exercise works because all three amounts use the same denominator; multiplying separately rounded percentage changes will not necessarily reproduce the reported figure.
Check which months and businesses are comparable
An acquisition completed in July brings only six months of sales into a calendar-year group that year. Its contribution can still make the following first half appear unusually strong. Look for comparable periods, disposals and changes to segment boundaries. For currency effects, establish which period’s rates were held fixed. Retranslating a foreign subsidiary’s accounts does not undo changes in the prices that subsidiary pays for imported components.
Follow the bridge into profit
An extra euro of revenue from a lower-margin acquisition need not generate the same earnings as an extra euro from existing products. Compare operating margin on a consistent definition, then examine acquisition charges, product mix and segment margins. If the issuer supplies a sales bridge but no profit split, report what you can establish about sales and leave the profit contribution unallocated. A precise estimate made from two incompatible margins can be less informative than a clearly identified gap.
Practical check
Rebuild the revenue bridge in euros before comparing organic growth rates. Mark any unexplained difference as a residual.