What is Cost of Capital?

Cost of capital is the return expected by those who provide capital for a business. It sounds like a technical finance term reserved for CFOs at public companies. That is a mistake. Ignoring this concept is dangerous for early stage founders.

Every dollar you put into your business has a price tag attached to it. Money is never actually free.

If you borrow money, the cost is the interest rate. If you take investment from an outsider, the cost is the return that investor expects to make. Even if you use your own savings, the cost is the opportunity cost of what that money could have earned if invested elsewhere.

There are two main buckets you need to understand.

The first is debt. This is usually the easiest to calculate. If you take out a loan with an 8 percent interest rate, your cost of debt is roughly 8 percent. There are tax implications that might lower the effective rate, but the interest payment is the primary driver.

The second is equity. This is where founders often get confused.

Equity is not free money. Investors expect a return based on the risk they are taking. Since startups are inherently risky, that expected return is high.

• Angel investors might expect a 20 percent return or more.
• Venture capitalists look for significantly higher returns to justify the failure rates in their portfolios.
• Your own equity requires a return that justifies the risk of not taking a stable salary.

It is helpful to look at how these two compare because they behave differently.

Debt is generally cheaper. The lender has the first claim on assets if things go wrong. Because they take less risk, they demand a lower return. However, debt increases the risk of bankruptcy if you cannot meet the payments.

Equity is more expensive. It sits at the bottom of the capital stack. If the company fails, equity holders usually get nothing. Because they take on the most risk, they demand the highest “cost” or return.

As a founder, you have to balance these. Relying only on expensive equity raises your overall cost of capital. Taking on too much debt makes the business fragile.

Why do you need to know this number today?

It sets your hurdle rate. Any project, product line, or expansion you launch needs to generate a return higher than your cost of capital.

If your cost of capital is 15 percent and you invest in a project returning 10 percent, you are technically destroying value. You are shrinking the economic value of the business even if you are generating revenue.

This framework helps you answer difficult operational questions.

• Should we expand to a new market?
• Should we buy this piece of expensive machinery?
• Should we accept the terms of this investment?

Calculating this in a mature company is a science. In a startup, it is often an art.

We do not always know the true risk premium. We cannot perfectly predict the volatility relative to the market. You have to be comfortable with some unknowns.

How much return do I genuinely need to justify the risk of this venture? Are the investors I am speaking with realistic about their expected returns compared to the stage of my business?

Understanding that capital has a cost ensures you treat it with respect. It forces you to deploy resources only where they create true value.