DayCents

Investing

Margin Loan Calculator

Borrowing on margin buys more than your cash allows, and amplifies the result — up and down. Interest is a certain drag, and there is a hard floor: if the portfolio falls to the margin-call price, the broker sells your holdings, often at the worst possible moment.

The minimum equity the broker requires — 25% is the regulatory floor, brokers often set more.

Margin call at a portfolio value of

$71,429

A 64.3% drop from here forces a sale.

Leverage cuts both ways. The 64% cushion sounds comfortable until a fast drop erases it and the broker sells without asking, locking in the loss. Margin is best kept small relative to the portfolio, and never used for money you cannot afford to have force-sold.

Interest cost over the period
$4,000
Return with leverage
$16,000
Return without borrowing
$15,000
Return on your equity
10.67%
Cushion before a margin call
64.29%
Position$200K
Your equity$150,00075%
Borrowed$50,00025%

How this calculator works

Interest is the amount borrowed times the margin rate, prorated over the holding months. The margin-call price is the amount borrowed divided by one minus the maintenance margin — the value at which equity falls to the required minimum. Levered return is the gain on the full position minus interest; unlevered return is the gain on your equity alone; return on equity divides the levered result by your equity.

Interest is treated as simple over the period rather than compounding daily, a small simplification. The margin-call price assumes the whole position moves together; a concentrated holding can trigger a call faster. Tax treatment of margin interest and the sequence of intra-period price moves are not modelled.

Try an example

Frequently asked questions

How does a margin loan work?

You borrow from your broker against the securities in your account, using them as collateral, and can invest more than your cash allows. Interest accrues daily. It magnifies gains when the market rises and losses when it falls, and the broker can demand repayment — by selling your holdings — if your equity drops too far.

What is a margin call?

A demand to add cash or securities when your equity falls below the maintenance margin — the minimum percentage of the position you must own outright. If you cannot meet it, the broker sells your holdings to restore the ratio, often at a loss and without waiting for your instruction.

At what price do I get a margin call?

When equity divided by portfolio value falls to the maintenance margin. Borrow $50,000 against a $200,000 portfolio with a 30% maintenance requirement and the call comes at about $71,400 — a 64% drop. The more you borrow, the smaller the cushion before that price is reached.

Is investing on margin worth it?

It raises expected return but also risk and cost, and adds the possibility of a forced sale at the worst time. For most investors the interest drag and the margin-call risk outweigh the benefit. Where it is genuinely useful is short-term liquidity, or modest leverage a portfolio can easily withstand — not aggressive borrowing.

How is margin interest taxed?

Margin interest may be deductible as investment interest expense, but only up to your net investment income and only if you itemise. Many investors get no deduction at all. Do not count on the tax benefit when judging whether the loan is worthwhile.

Disclaimer: DayCents provides this calculator for educational purposes only. Results are estimates based on your inputs and the stated assumptions — they are not financial advice, a quote, or an offer of credit. Consult a qualified financial professional before making major money decisions.