Rex says
The fast lane for the math you almost remember from school. Type the numbers, get the answer, move on with your day.
Try a scenario
Click to load — tweak from there.Inputs
Result
Your share of voice
8.0%
Excess share of voice (SOV − SOM)
2.0%
Projected annual share change (points)
0.10
Projected market share in 5 years
6.5%
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How to use this
- 1Enter your annual advertising spend ($).
- 2Enter total category advertising spend ($).
- 3Enter your current market share (%).
- 4Read your your share of voice on the right — it updates as you type.
- 5Hit Share to keep the scenario or send it to someone.
About this calculator
Share of voice (your ad spend or impressions as a percentage of total category advertising) tends to predict future share of market with a lag, a relationship advertising researchers have documented for decades across categories: brands that advertise above their market share tend to grow share over time, and brands that under-advertise relative to share tend to lose it. This calculator computes your share of voice from your spend and estimated total category spend, compares it to your current share of market, and calculates the 'excess share of voice' (SOV minus SOM), which is the standard leading indicator marketers use to forecast share gain or loss. A positive excess SOV of 10 points, using the commonly cited Peckham/IPA relationship, roughly predicts about half a point of share gain per year, though the actual multiplier varies heavily by category maturity, price elasticity, and distribution. Use this to sanity-check whether your media budget is proportionate to your ambitions — a challenger brand trying to double market share within three years needs SOV meaningfully above its current SOM, not equal to it, and a market leader can often sustain share with SOV somewhat below SOM due to incumbency advantages.
Worked example
Using the values the calculator loads with:
Inputs
- Your annual advertising spend: 2000000 $
- Total category advertising spend: 25000000 $
- Your current market share: 6 %
Results
- Your share of voice: 8.0%
- Excess share of voice (SOV − SOM): 2.0%
- Projected annual share change (points): 0.1
- Projected market share in 5 years: 6.5%
What each field means
Inputs
- Your annual advertising spend ($)
- The your annual advertising spend used in the calculation, measured in $. Starts at 2000000 $ so you have a working example on load.
- Total category advertising spend ($)
- The total category advertising spend used in the calculation, measured in $. Starts at 25000000 $ so you have a working example on load.
- Your current market share (%)
- The your current market share used in the calculation, measured in %. Starts at 6 % so you have a working example on load. Accepted range: 0–100 %.
Results
- Your share of voice
- Returned as a percentage and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Excess share of voice (SOV − SOM)
- Returned as a percentage. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Projected annual share change (points)
- Returned as a decimal number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Projected market share in 5 years
- Returned as a percentage. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
Where do I get total category spend data?
Nielsen Ad Intel, Kantar, or Vivvix/MediaRadar publish category ad-spend tracking for most consumer categories. For niche B2B categories without syndicated data, estimate from competitor SimilarWeb ad spend estimates or public earnings call disclosures of marketing budgets.
Is the 0.05 multiplier reliable?
It's a rough historical average from IPA/Nielsen studies (roughly half a share point of gain per 10 points of positive ESOV per year), but it varies by category. Fast-moving consumer goods categories tend to track closer to this; durable goods and B2B with long sales cycles move much slower and less predictably.
What if my ESOV is negative?
A sustained negative ESOV predicts gradual share erosion even if nothing else changes, since competitors are more present in the consideration set. This isn't automatic or immediate, but it's a warning sign worth acting on before share loss shows up in the sales numbers.
Does this apply to digital-only or DTC brands?
The underlying mental-availability logic still applies, but SOV is harder to measure cleanly in digital because auction dynamics and targeting mean 'share of voice' isn't a single number the way it is in linear TV. Use it as a directional framework, not a precise digital metric.
Accuracy and limitations
- Results are rounded for display; the underlying calculation keeps full precision.
- Very large or very small inputs may hit floating-point limits in the browser.
- Inputs outside the accepted range are clamped rather than rejected.
Related tools
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). Share of Voice vs. Share of Market Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/share-of-voice-calculator
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/share-of-voice-calculator" target="_blank" rel="noopener">Share of Voice vs. Share of Market Calculator — RevenueLab</a> (2026).</p>
Source: [Share of Voice vs. Share of Market Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/share-of-voice-calculator) (2026).