Picking an interest rate for a family loan

There is no single right number. Most families land on one of three answers: zero, a small token rate, or the IRS minimum. Here is how to pick between them without making it weird.

The three answers most families land on

Ask ten people how much interest to charge a family member and you will hear the same three answers, over and over.

• Zero percent. You just want your money back. This is the most common choice for small loans between people who trust each other.
• A token rate. Something small, often 1 to 3 percent. Enough to feel fair, not enough to feel like a bank.
• The AFR. The minimum rate the IRS publishes each month. A common pick for large loans, because it keeps the tax side simple.

Which one fits depends on three things: how big the loan is, how long it will run, and what feels right between the two of you. Let's walk through each option, then look at the math.

Zero percent is common, and usually fine

Most family loans are acts of help, not investments. If your sister needs $2,000 for a car repair, charging her interest can feel strange. It is completely normal to lend at 0%, and a lot of families do exactly that.

For small loans, zero interest rarely creates problems. The tax rules that care about below-market loans include a carve-out for most loans of $10,000 or less, so a small interest-free loan between family members generally does not raise IRS issues. More on the tax side in a moment, and in our full guide to IRS rules for family loans.

The real risk with 0% is not the IRS. It is fuzziness. When no interest changes hands, people are tempted to skip the paperwork too, and that is where family loans go wrong. A 0% loan still deserves a written agreement and a payment schedule. The rate can be zero. The record should not be.

Why some lenders charge a token rate

Plenty of family lenders charge a small rate on purpose, even when they do not need the money. Three honest reasons come up again and again.

Fairness to the lender

Money sitting in a savings account earns something. If you pull $10,000 out of savings and lend it to your brother for three years, you give that up. A token rate, even 2 percent, means the loan does not quietly cost you money for doing a kind thing.

Seriousness

Interest changes how a loan feels. A 0% loan can drift toward "pay me back whenever." A loan with a rate and a schedule reads like a real obligation, and borrowers tend to treat it like one. Many lenders say the small rate is less about the money and more about the signal it sends.

The borrower's dignity

This one surprises people. Some borrowers actually prefer to pay a little interest. It turns the arrangement from a favor into a deal between equals, and that can make the next family dinner a lot more comfortable.

The AFR: the floor the IRS cares about

The applicable federal rate, or AFR, is a set of minimum interest rates the IRS publishes every month. There are separate rates for short-term, mid-term, and long-term loans. You can always find the current numbers on the IRS website at https://www.irs.gov/applicable-federal-rates. The rates change monthly, so the table to check is the one for the month the loan is made.

Here is why it matters. When someone lends a large amount at less than the AFR, the tax rules can treat the interest that was not charged as if it had been. The IRS calls this imputed interest: the lender can owe tax on interest they never actually received, and the forgone interest can also count as a gift to the borrower. It is a strange rule, and it mostly bites on larger loans.

Because of that, a common approach for loans in the tens of thousands and up is to charge at least the AFR in effect when the loan begins. The AFR usually sits far below what a bank would charge, so the borrower still gets a genuinely good deal, and the lender stays clear of the imputed-interest mess.

Simple vs. amortized, in plain English

Once you have a rate, there is one more decision: how the interest is applied. Two methods cover almost every family loan.

Simple, or flat, interest is one calculation on the original amount. Lend $1,000 at 5% for one year and the interest is $50, period. The borrower repays $1,050, either at the end or spread across payments. It is easy to explain, easy to check, and a fine fit for short loans.

Amortized interest is what banks use. Each month, interest is charged only on what is still owed. The payment stays the same, but early payments are mostly interest and later payments are mostly principal. As the balance shrinks, the interest shrinks with it. At the same rate and term, amortized usually costs the borrower a bit less than flat interest, and it feels fairer when the loan is being paid down steadily.

Neither method is wrong. What matters is that the agreement says which one you are using, so nobody recalculates the balance differently two years in.

A worked example

Say you lend $10,000, repaid in monthly payments over three years, amortized. Here is what different rates actually do to the numbers.

Two things jump out. First, a token rate barely moves the payment: going from 0% to 2% adds about $9 a month. Second, even 5% costs the borrower far less than a typical bank personal loan or a credit card would. That is the quiet power of a family loan. The borrower saves real money, and the lender can still come out ahead of a savings account.

Want to try your own numbers? The free loan calculator lets you test any amount, rate, and term, and shows the full payment schedule before you commit to anything.

How to bring it up

The rate conversation goes better when it is a proposal, not a decree. Something like: "I can do $10,000 over three years. I was thinking 2 percent so I'm not losing ground on it. Does that feel fair to you?" gives the other person room to respond.

It also helps to name the comparison out loud. If the bank would charge 12% and you are asking 3%, say so. The borrower hears the whole picture, and the rate stops feeling like a judgment and starts feeling like what it is: a discount from a person who cares about them.

Writing the rate into the agreement

Whatever number you land on, put it in writing. A clear rate clause covers four things:

1. The number. "4% per year," not "some interest."
2. The method. Simple or amortized, so the math is repeatable by both sides.
3. The schedule. Attach the full payment schedule, with every amount and date, plus what happens if the loan is paid off early.
4. Signatures. Both people sign, so nobody remembers the deal differently later.

Our guide to the family loan agreement walks through the whole document, clause by clause.

This is the part Kinlend was built for. You enter the amount, rate, and term. Kinlend generates the payment schedule and a loan agreement you both e-sign. It also shows an all-in APR, so both sides see the true cost of the loan, not just the sticker rate. From there, payments are tracked with two-sided confirmation: the borrower marks a payment sent, the lender confirms it arrived. Gentle reminders keep things on schedule. Kinlend is not a lender, and no money moves through it. It just keeps the record straight, on the web and on iPhone.