TAM SAM SOM Calculator

What Are TAM, SAM and SOM?

TAM, SAM and SOM size a market in three steps: everyone who could buy, the part you can serve, and the part you can win. They're the numbers on the market size slide of almost every pitch deck, business plan and go-to-market presentation, and SlideModel's free TAM SAM SOM Calculator works them out and draws that slide for you.

• TAM (Total Addressable Market): the yearly revenue you'd earn with 100% of the market and no competitors.
• SAM (Serviceable Addressable Market): the part of TAM your product, price, geography and channels can actually serve today.
• SOM (Serviceable Obtainable Market): the part of SAM you can realistically win in the next three to five years.

Some presentations add a fourth layer above TAM, PAM (Potential Available Market): everyone who could ever buy something like your product. Investors rarely ask for it, but it helps when the audience needs to see the wider market first. Turn on "Add PAM above TAM" to size it and draw a PAM, TAM, SAM and SOM slide.

How to Calculate TAM, SAM and SOM

Bottom-up (recommended). Count the buyers and multiply by what each pays per year.

1. Count all possible buyers. TAM = all possible buyers × annual price. Use a source you can name, such as a census or an industry count.
2. Apply your filters. SAM = the buyers left after your filters (segment, size, region, channel) × the annual price.
3. Estimate what you can win. SOM = the customers you can win in three to five years × the annual price. Check it against your sales capacity: reps × deals per rep per month × months. Use the smaller number.
4. Check and download. Read the checks under the preview, pick a shape and colors, and download the slide.

Top-down. Start from a published market size and narrow it: SAM = TAM × the share you can serve; SOM = SAM × the share you expect to win. It's quick, and it's best used to check a bottom-up number, not to replace it. Fill in both and the calculator compares them.

Value theory. For a new category with no existing spend, estimate the value you create per customer and the share of it you can charge for, then size it bottom-up.

A Worked Example

FieldBoard, an illustrative example, sells project management software to US construction firms for $3,600 a year.

SOM is 2.7% of SAM and 0.35% of TAM: modest, explained and easy to defend. A top-down check from a $3.1B industry figure lands within 1.2× of the bottom-up TAM, so the two methods agree. Load the B2B SaaS example to see the slide.

What Investors Look For

• A bottom-up build. In a survey of 30 VCs by Pear VC, the most consistent criticism of market size slides was revenue built on "a percentage of a large market."
• Shares that make sense. Many young companies show a SOM of 1% to 5% of TAM. Over 10% invites questions, and a SAM above half of TAM suggests the filters are too loose.
• Sources and a year for every number, and one geography across all three layers.
• The assumptions on the slide, not just three bold numbers in three circles. The PowerPoint deck adds an assumptions slide with every formula and source.

The checks under the preview flag each of these as you type.

Common Mistakes

• Leading with TAM as if it were the opportunity.
• "We only need 1% of the market," with no bottom-up build behind it.
• A global TAM next to a local SAM.
• Mixing yearly and lifetime revenue, or sizing a marketplace on gross transaction value instead of your take rate.
• No source, or $B and $M mixed on one slide.

How to Present Market Size in a Pitch Deck

The market size slide usually comes right after the problem and solution: once the audience knows what you sell, show how big the opportunity is and how much of it you can win. Nested circles are the standard investor slide; a funnel suits internal strategy presentations; bars drawn true to scale are the honest choice when SOM is a tiny fraction of TAM. Whatever the shape, put the method, the main assumptions and the sources on the slide or the next one, and say the SOM out loud: it's the number you're asking investors to believe.

SlideModel's article on TAM, SAM and SOM in presentations covers the storytelling side, and the guide to creating an investor pitch deck shows where the slide fits. To show which assumption moves your SOM the most, test the price, win rate and sales capacity on a tornado chart.

TAM SAM SOM Templates

The calculator builds the slide from your numbers; a template gives you a designed layout to paste them into. For more designs, such as concentric circles with icons, 3D layers or PAM-TAM-SAM-SOM diagrams, browse SlideModel's TAM SAM SOM PowerPoint templates, editable in PowerPoint, Google Slides and Keynote. The financial side of the same deck, from revenue to break-even, is covered in the guide to the financial projections slide.