How this number is made
Margin interest is the cost of the broker’s loan against your shares. This page uses simple interest on the amount borrowed for the days you type. The rate can change, the broker can raise the maintenance requirement, and a falling price can force a sale. None of that is in the interest figure.
- Use the rate on the margin agreement, not the stock’s dividend.
- Days are calendar days the balance stays outstanding.
Formula
Interest = borrowed × rate × days ÷ 365.
Worked example
With the figures already in the form, interest for those days is $221.92.
Questions
Is margin interest deductible?
Sometimes, as investment interest, with limits and only if you itemize. This page is the interest, not the deduction.
What is a margin call?
A demand for cash or shares when the equity in the account falls below the broker’s line. This page does not compute that line.