A majority of America’s small business owners are not saving for retirement. Many know they should, but feel that saving will hurt their business. According to David Deeds, Schulze Professor of Entrepreneurship at the University of St. Thomas in Minneapolis, small business owners do not save because they consider the business their retirement plan. “The plan is that when they retire, they are either going to transfer the business to a family member in exchange for a share of future wealth or a buyout or they are going to sell it off and turn that into cash.”

However, many circumstances may prevent the sale of a small business. Even if the business can be sold, the sale may not provide enough income to cover one’s entire retirement. Entrepreneurs may also have to retire earlier than they expected due to health problems or other unforeseen events.

Having a well-rounded retirement plan can help protect entrepreneurs against these and other risks. Here are five things small business owners need to know to plan their retirement effectively.

First, know the numbers. Small business owners should calculate how much money they will need to live on in retirement. Factors such as where they want to live (a pricier home or a modest apartment), how they want to spend their time (traveling or working part-time), and healthcare costs play an important role in this assessment.

Once they have an idea of how much they will need, entrepreneurs should get a valuation of their business to see if its sale or transfer is a viable retirement option. As part of their valuation, small business owners should consider whether the business can operate without their involvement. If it cannot, it may be difficult to sell or generate income from it once the business owner retires.

Next, determine a goal. This might seem elementary, but the power of having a firm vision for the future of a small business and retirement cannot be overstated. Entrepreneurs who set firm goals take steps to make sure their goals are met. This helps them find the best tools to save and also prepares them to wind down the business when it is actually time to retire.

Know the best tools. Business owners do not need to move significant amounts of money from their business in order to start saving for retirement. Investing just a little bit can help entrepreneurs save on their present-day taxes until they make withdrawals in retirement. There are four main instruments to choose from.

SEP-IRA: Like a traditional IRA, this retirement plan is tax-deductible. For returns filed this year, small business owners can contribute up to 25% of their income or $54,000. A SEP-IRA is a great retirement plan for sole proprietors because it is self-directed, but the 401(k) described below offers similar benefits but may be more cost effective due to lower administration fees.

Simple IRA: This plan is designed for entrepreneurs who employ 100 or fewer employees. Like for a 401(k), contributions are taken directly from employee paychecks and are pre-tax. Contributions cannot exceed $12,500 in 2017, but employees who are 50 or older may contribute up to $15,500.

Solo 401(k): This plan is for sole proprietors but may include the proprietor’s spouse. Proprietors may contribute up to 25% of their salary plus up to $18,000 ($24,000 for people aged 50 or older), but the total contribution may not exceed $54,000. A spouse who works in the business may also contribute the same amounts.

Simple 401(k): Small businesses with 100 or fewer employees may utilize this plan. Owners and employees have the option to contribute up to $12,500 this year, or $15,500 for people aged 50 and older. This plan also allows for borrowing against it and making penalty-free withdrawals to cover financial hardship.

A sole proprietorship, a partnership, limited liability company, or corporate can qualify for every plan except the SEP-IRA.

Keep investments simple. Most small business owners should probably invest in a globally diverse collection of low-cost index funds. An index fund invests broadly across entire markets like the U.S. stock market, U.S. bond market, and developed foreign stock markets.

Another option for simple investment is a target-date fund, which automatically adjusts the balance of fixed-income investments based on age and the selected date.

Diversify all investments. Diversification does not apply only to the retirement plans described above but to any asset a small business owner may choose to invest in. Getting all of one’s savings or investments caught in one basket can be risky.

This is especially true of home ownership. The real estate market is cyclical, so it can yield high returns or unexpectedly big losses. Small business owners who place most of their net worth in their home are cautioned to spread their wealth around.

Put it all together. With their numbers as their foundation and their goals in mind, small business owners have terrific opportunities to save for retirement. By utilizing the tools we describe to invest in a diverse portfolio, more small business owners can effectively build their wealth without hurting their present-day business growth.