Share of Voice Calculator
Your share of voice against up to three competitors, and the excess share of voice over market share that a widely cited rule of thumb links to growth.
Share of voice is your share of whatever is being counted — impressions, mentions, search visibility or spend — against the set of competitors you name.
How the share of voice calculator works
Share of voice is your share of whatever is being counted — impressions, mentions, search visibility or spend — against the set of competitors you name. On its own it is a comparison; against market share it becomes a prediction.
The rule of thumb from long-run advertising studies is that a brand whose share of voice exceeds its market share tends to grow, at very roughly half a point of market share a year for every ten points of excess. The calculator shows the excess and that indicative figure.
Formula: SOV = yours ÷ (yours + competitors); ESOV = SOV − market share; indicative growth ≈ ESOV × 0.05 points per year
Worked examples
| Inputs | Share of voice | Note |
|---|---|---|
| Challenger brand | 30% | 30% of voice against 25% of the market: +5 points |
| Leader under-investing | 30% | 30% of voice against 40% of the market |
| Four-brand category | 25% | even split |
FAQFrequently asked questions
What can share of voice be measured in?
Anything comparable across the set: paid impressions, ad spend, social mentions, press coverage, search visibility. Use one measure for all the brands in the same period; mixing measures makes the shares meaningless.
What is excess share of voice?
Share of voice minus market share. Long-run studies of advertising effectiveness found that brands with a positive excess tend to gain market share and those with a negative one tend to lose it, at roughly half a point of share a year for every ten points of excess — a tendency, not a law.
Which competitors should I include?
The set a buyer actually chooses between. Leaving out a large competitor inflates everyone else's share; including a distant one deflates them. Three named competitors cover most categories; a long tail can be added as one combined figure.
Is a high share of voice always good?
Only relative to market share and cost. A small brand outspending its share is investing in growth; a large brand far above its share may be spending past the point of return. The excess figure is the one to watch, alongside what it costs.
Where these figures come from
- Interactive Advertising Bureau — measurement guidelines — the impression and viewability definitions CPM depends on
- Advertising Standards Authority — the UK advertising regulator
Last checked: September 2026. These are standard industry definitions; where platforms disagree, the page says so.