These metrics form your foundation. 4 are universal for every business, and additional ones adapt to your industry or business model. They connect to answer your core questions, turning gut feelings into data you can act on.

Both metrics reveal the efficiency of your core offerings, answering "Is my product or service profitable enough to sustain me?" A solid Gross or Contribution Margin gives you "breathing room" to cover fixed costs like rent or salaries, and signals if scaling (e.g., more ads) makes sense. Low margins? It's a red flag to rethink pricing, cut variable costs, or adjust your offering before growth drains your cash.

An average SMB has a gross profit margin somewhere between 35–40%, but what's reasonable highly depends on what kind of business you are running and your business strategy:

Customer Acquisition Cost (CAC) is the total expense a business incurs to acquire a new customer, including all sales, marketing, and related costs (e.g., ads, salaries, time value) divided by the number of new customers gained. This metric captures the efficiency of your demand generation efforts.

CAC answers "How easy is it for me to get customers?" and "If I had $1,000,000, how many could I acquire?" It also gauges marketing funnel efficiency. Just about every metric in your marketing funnel ends up getting wrapped up into CAC. It encompasses online conversion rates, social media engagement, and sales close rates all into one number. There is no one good number for CAC for your business, but if you compare it with Gross Profit Margin and LTV, it reveals if acquisition is affordable. If your gross margin and or LTV is higher, you can afford to spend more on CAC.

Remember what the purpose of this metric is for. It's to help you make decisions. Let's expand on the example and how you should handle it. Let's say the following month you spent $5,000 on overhauling your website and making it convert much better. Suddenly, your costs jump to $16,000, and let's say you get better conversion rates so you got 70 new customers from the same ads and salaries and time investment. If you included this in your CAC, it would have gone up from $200 to $228. The very next month, you didn't need to spend $5,000 again on your website, but the benefits stayed, and so you got 70 customers after only spending $11,000, so your CAC is $157. Your CAC from month to month shot up, and then back down, but you only became more effective at attracting customers. It all had to do with how you wanted to account for the $5,000 website cost, because the effects of that are going to be for months or years, but the cost is all in one month. How you deal with this situation is entirely up to what sorts of questions you're trying to ask and what decisions you are trying to make.

What a reasonable CAC is for you is highly dependent on how valuable your customers are. If you are trying to sell a multi million dollar contract, it would not be unreasonable for you to spend millions of dollars to acquire a customer. However, industries do have averages, and they can start setting expectations. I do want to caution you however. CAC is not like Gross Profit Margin or Net Profit Margin. It's not covered under GAAP. There's not one standard that everyone uses. And even then, the way people typically calculate CAC is the simple way where they have all the numbers. They don't do things like include the time value of all the work you put in on your marketing efforts. Also, you'll notice that CAC can vary wildly even within industry. With that said, here a few examples.

And then also, if the revenue you expect to generate from this person happens over a long enough time period, you need to discount future cash flows. In a technical sense, you should do this regardless, but it doesn't matter so much if the revenue generated is just for the next year or two.

You want this to include everything that a customer will ever provide you. You want a complete and total view of their full value to you. Some parts of this are harder to calculate, and sometimes they will be negligible as well, and so you can skip them, but you should do so purposefully.

Let's say that you are a restaurant, and for people you would classify as a "loyal" customer, they come once a month, spend about $50 each time. We'll assume you're a higher end restaurant, so your gross margin might be 65%, so the value to you of this one person coming is $32.50 per month. You expect the average loyal customer is with you for two years. Some people move away, some people's incomes change, or maybe they have a kid, and now they don't go out as much. Regardless, you expect a loyal customer will provide you $32.50 worth of value on average 24 times before they churn. That's $780. So how much would you as a restaurant owner be willing to pay to get a loyal customer when you know on average they provide you $780 of value?

You are a roofer, and your average client pays you $10,000 and that costs you $7,000 to provide to them, so their initial value to you is $3,000. They won't need their roof replaced anytime soon, so there is no future revenue you need to account for. So is their CLTV $3,000? Some people would say so, but I don't think that paints the full picture.

How much is it worth to you if they leave you a 5 star review on google? What if they leave a glowing testimonial you can put on your website. What if they put a sign out in their front yard so all their neighbors who also just received hail damage can see who put on that beautiful roof? What is it worth to you if they post on social media saying how great of a job you did? What about a literal referral? If a customer did all of that for you, how much more business would they drive to you? The way I would determine how much it's worth to you, is by how much cost to acquire a customer it saves you. A roofer might pay $100-$400 for high quality leads, so if you get 1-3 more leads from customers you serve, their value to you changes from $3,000 to $3,100 - $4,200.

You will find several formulas online that look something like this. Average Revenue per Account per period * Gross Margin / Churn Rate per period, and that's a decent starting point.

Second, Gross Margin is a really solid choice to use to turn lifetime revenue into lifetime 'value' but I would prefer Contribution Margin instead. If you found a way to save $3 on your shipping costs, that would obviously mean selling products to your customers is worth $3 more dollars to you, but because shipping costs are an example of a variable cost that isn't included in COGS, your CLTV wouldn't change if you use Gross Profit Margin compared to using Contribution Margin. Lastly, it only includes revenue, not any of the other 'value' producing actions that we've talked about so far.

CLTV can vary wildly. As an example, an architecture firm CLTV might be over $1,000,000 while a seller of a single non-consumable item on Amazon might have a CLTV as low as $2. And it's hard to tell you what typical values for you should be, because LTV is defined differently in a lot of different contexts. Some people just consider it total amount of revenue and don't subtract the variable costs, which in my opinion defeats the purpose of calling it 'value'. Instead, we'll talk about the levers you can pull to change your CLTV

Net Profit Margin is the ultimate measure of your business's profitability, showing what percentage of revenue remains after all costs including variable (like materials), fixed (like rent), and other expenses (like taxes or interest). Defined under Generally Accepted Accounting Principles (GAAP), it's calculated as: (Net Income / Revenue) x 100. Net Income is what's left after COGS, operating expenses, and non-operating costs (e.g., loan interest) are subtracted from total revenue. It's the bottom line that answers, "Am I truly making money?"

This metric tells you if your business is worth the time, money, effort, and stress. Can you pay your bills and still thrive? It's the final check after Gross Profit Margin, LTV, and CAC. If all of those metrics are looking good but your Net Profit isn't, you face a volume problem. You are efficiently acquiring customers and providing your product or service, but you don't have enough customers to cover all your other expenses. A healthy Net Profit Margin ensures sustainability, signals to investors or lenders your viability, and guides decisions like hiring or expansion.

You can calculate Net Profit Margin for your whole business, but breaking it down by product line, department, or project uncovers profitability drivers. It spots inefficiencies (e.g., a 5% margin product vs. a 20% winner) or cost leaks. The challenge? It requires detailed cost allocation across categories, often needing advanced software or manual tracking. Start with the big picture, then segment as resources allow.

This ratio tells you if you are acquiring high enough value customers to justify your costs of acquiring them. Traditional advice is to shoot for at least a 3 to 1 ratio, but traditional advice often doesn't include all the things I've told you to include in LTV or CAC. In reality, according to provable, mathematically true principles, after you account for every little thing, the value of your time, the network effects of a new customer, the word of mouth from happy customers, heck even the experience your team gains in providing the service, after you account for it all, you should be willing to acquire a customer if their value to you is even $1 more than their cost to you. The problem as you can clearly see is that it's very difficult to account for all of that, and so the 3:1 ratio becomes a reasonable 'fudge factor' to make sure you have enough margin that you don't have to worry about all the little things. If I had a machine that doubled your money. You wouldn't complain to me that it only had a 2:1 return. The same goes for LTV-CAC. The more you account for all the aspects of CAC and LTV, the closer to a 1:1 ratio you can justify, and the less you can account for, the more fudge factor you need.

If your Gross Profit Margin is looking good, but your net profit margin is not, it means you are spending too much on your costs not directly related to providing your product or service as a percentage of your revenue. You've got two options from here. You can either decrease your costs or you can increase your revenue faster than your non-direct costs increase. In general, you should prefer increasing your revenue faster. One mistake that small businesses often make is not spending enough on marketing.

The mental problem business owners run into, is if they aren't making money, they are hesitant to invest more money in themselves.

Last thing I want to point out in this example, is the LTV of one customer was $60 ($100 * 60%) and their CAC was $20 ($1,000/50). If you didn't know those numbers, and that you had a 3:1 ratio there, you wouldn't be confident in tripling your marketing budget. You would hear triple your marketing budget while you aren't making any money, and you'd look at the person like they were insane. But looking simply at the numbers where you make $60 per customer and it costs you $20 to get a customer, suddenly you would feel insane not to make that trade as many times as you can.