Tools/Visa-holder finance/Prepay an Education Loan or Invest✓ CHECKED AGAINST WORKED EXAMPLES · SEP 29, 2026

Should I prepay my home-country education loan or invest in dollars?

Compare paying down a loan in another currency with investing the same extra money each month in dollars, taking the loan currency’s change against the dollar into account.

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Loan balance, in dollars$An example, not a quote: the balance left, converted to dollars at today’s exchange rate.Loan interest rate%The rate on the loan, in its own currency. An example: replace it with your loan statement.Years left on the loanyearsExtra you can put toward it each month$In dollars, on top of the scheduled payment. The same amount is used either way.How much the loan currency falls against the dollar each year%An assumption, not a forecast: 0 means no change. A currency that weakens makes each fixed payment cost fewer dollars, which makes the loan cheaper in dollar terms; enter a negative number if it strengthens.Investment return in dollars, before tax%A yearly return in ordinary (not inflation-adjusted) dollars. An assumption, not a forecast.Tax on investment growth%Taken from the growth at the end. Use 0 for a Roth or 401(k) you will withdraw from tax-free.

PREPAY OR INVESTPREPAYING COMES OUT AHEAD

$4,103

A $40,000 loan at 10.00%, with $300 extra a month for 8 years, is finished 3 years 4 months early by prepaying and saves $8,201 of interest. After 15% tax on growth, if investments earn 7.0% a year, the two end $4,103 ahead for prepaying ($3,239 in today’s dollars). Investing comes out ahead only if it earns more than about 11.76% a year in dollars; prepaying earns a certain 10.00% a year, and investing does not.

Loan paid off

4 yr 8 mo

Interest saved

$8,201

Cost in dollars

10.00%

Break-even return

11.76%

UNDERSTAND YOUR RESULT

LIBRARY CHAPTERGood Debt and Bad Debt: Judging What a Loan BuysFour questions that replace the good-debt and bad-debt labels, worked examples of how the term changes the cost of a car loan and a mortgage, how to judge education debt, and when interest deductions actually help.LIBRARY CHAPTERAvalanche or Snowball: Choosing a Payoff OrderWhy paying the highest rate first saves the most interest, when paying the smallest balance first is worth its cost, what the research says about motivation, and how to set up either method so it runs on its own.

Terms:Prepay debt or invest

Investments minus what you still owe, before tax, in future dollars

PrepayInvest

Before tax, counting what you still owe, the prepay route is $3,380 ahead after 8 years. At the end it holds $41,486 and owes nothing; the invest route holds $38,106 and owes nothing too, but has paid $8,201 more interest.

Which comes out ahead at different investment returns

Yearly return	Prepay, after tax	Invest, after tax	Ahead
3%	$38,595	$31,903	Prepay by $6,693
5%	$39,691	$34,204	Prepay by $5,487
7% (yours)	$40,813	$36,710	Prepay by $4,103
9%	$41,963	$39,438	Prepay by $2,525
11%	$43,140	$42,405	Prepay by $735

The two are equal at about 11.76% a year. Below it prepaying wins, above it investing wins. The loan costs 10.00% in dollars; tax on the growth pushes the break-even higher.

What moves the needle

Each row re-runs the calculation with one change. Click to apply.

How it's computed

FORMULA

Cost in dollars: monthly rate = (1 + loan rate ÷ 12) ÷ (1 + yearly currency fall)^(1/12) − 1, times 12

Payment = balance × r ÷ (1 − (1 + r)^−n) at that dollar rate

Prepay: the extra goes to principal each month; once the loan is gone the whole payment plus the extra is invested each month

Invest: the loan runs its term and the extra is invested each month; after-tax value = investments − tax rate × growth

The loan is treated as costing 10.00% a year in dollars: its own 10.00% rate less the loan currency’s 0.0% yearly move against the dollar. That is an approximation that treats the dollar cost as a level payment at that rate. The currency change is an assumption you set, not a forecast: currencies can swing far from any average.
The comparison is in dollars and assumes your income and investments are in dollars. If you will earn or live in the loan’s currency, the currency change does not apply and the loan’s own rate is what matters.
Investments earn a steady 7% a year in ordinary dollars, taxed at 15% on the growth at the end. Real returns are not steady and can be negative for years; prepaying earns a certain 10.00% in dollars.
Not modelled: any deduction of the loan interest in the home country (some countries allow one to residents), any U.S. treatment of interest on a foreign loan, a prepayment charge, and the cost of sending money abroad.
The balance, rate and term are examples until you replace them with the figures on your loan statement. Money sent abroad is hard to bring back; money invested can be sold.

WORKED EXAMPLE · SAMPLE NUMBERS

Cost in dollars: 10.00% less a 0.0% currency move is 10.00%. Payment on $40,000 for 8 years at that rate: $607 a month. Prepay: $907 a month clears the loan in 4 years 8 months, then that amount is invested, reaching $41,486, $40,813 after 15% tax on growth. Invest: $300 a month at 7.0% reaches $38,106, $36,710 after tax, having paid $18,269 of interest.

SOURCES

[1]Compound InterestInvestor.gov, U.S. Securities and Exchange Commission [2]Topic no. 409: Capital gains and lossesInternal Revenue Service [3]Publication 970: Tax Benefits for Education (student loan interest)Internal Revenue Service

HSBuilt by Hussain Sehorewala · checked against worked examples · Sep 29, 2026

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Questions about this result

It depends mainly on the loan’s cost in dollars against what you expect to earn investing after tax. Prepaying earns a certain return equal to that cost; investing earns more if markets cooperate and less if they do not. On the example on this page, a $40,000 loan at 10% with $300 extra a month, prepaying comes out ahead of investing at a 7% return.

Your loan payments are a fixed amount of the loan’s currency. If that currency weakens against the dollar, each payment costs you fewer dollars, so the loan is cheaper in dollar terms than its rate suggests; if it strengthens, it is dearer. On the example, a 10% loan in a currency that falls 3% a year against the dollar costs about 7.02% in dollars, and prepaying then comes out $1,016 ahead instead of $4,103.

More than the break-even shown on this page. For the example with no currency change it is about 11.76% a year after a 15% tax on the growth; with the loan currency falling 3% a year it is about 8.24%. In a tax-free account, set the tax to 0.

Then the exchange rate does not change what the loan costs you: leave the currency change at 0 and compare the loan’s rate with what you can earn there. The dollar comparison is for people who earn and invest in dollars while the loan stays in another currency.

Some countries let residents deduct education-loan interest; the U.S. has a student loan interest deduction with its own conditions. This page does not model any of them, so if you can claim one, prepaying saves less than shown.

Exchange-rate swings, deductions of the interest, prepayment charges, the cost of transferring money, and your need for cash: money sent to a lender is hard to get back. It compares two steady paths.

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Investments minus what you still owe, before tax, in future dollars

Which comes out ahead at different investment returns

What moves the needle

How it's computed

Questions about this result

Natural next questions