Late fee
$29.59
Free calculator
Type the amount owed, how many days late it is, and the annual late fee rate stated on your own invoice terms. What's owed updates as you type. This does the arithmetic on your rate. It does not tell you what rate you're legally allowed to charge. No email, no gate, nothing leaves this page.
The calculator
The boxes start filled with an illustrative example, not a benchmark. Replace it with your own numbers. This tool applies the rate you already state on your terms, it does not set or validate that rate for you.
The unpaid invoice total the late fee applies to.
How many days past the due date the invoice is today.
This is the rate stated on your own invoice terms, not a rate this tool calculates for you. Invoices often state it as a monthly rate instead, commonly 1.5% a month, which is 18% annualized. This tool does not tell you what rate you're allowed to charge, only does the arithmetic on the rate you already state.
Total now owed
At 18% a year, 25 days late on $2,400.00 works out to a $29.59 late fee, using simple interest on the amount owed.
late fee = amount owed × (your stated annual rate / 100) × (days late / 365) total owed = amount owed + late fee
This is simple interest, spread evenly across the days late, on whatever annual rate you enter. It is arithmetic, not legal advice: it does not know your jurisdiction and it does not know what rate your contract or local law allows. Check your own jurisdiction and contract terms before charging a late fee.
See it on your own data Real numbers from your Shopify store, not a guess.
This is pure arithmetic on whatever rate you enter. It does not tell you the maximum late fee rate you're legally allowed to charge. That maximum varies by jurisdiction, by state or country, and it also depends on how the fee is structured: whether it's framed as interest on an unpaid balance or as a flat contractual penalty can change what's enforceable, and that framing is a legal question, not an arithmetic one.
Check your own jurisdiction and your own contract or invoice terms before you charge a late fee. This tool is not legal guidance, and nothing on this page should be read as telling you what rate is allowed where you operate.
Questions
In many places, yes, but it varies by jurisdiction, state or country, and sometimes by the type of business or contract involved, and this tool has no way of knowing where you or your customer are located. Do not treat anything on this page as telling you what rate is legally allowed. Check your own jurisdiction's rules and your own contract terms, ideally with someone qualified to advise on them, before you set or charge a rate.
Often as a monthly rate rather than an annual one, commonly around 1.5% a month on many standard invoice templates. This calculator asks for the annual rate, so a stated monthly rate needs to be multiplied by 12 first: 1.5% a month is 18% a year.
This calculator uses simple interest, the annual rate applied once across the full number of days late. Some contracts instead compound the fee, for example adding it monthly so each month's fee is calculated on a growing balance that already includes prior late fees. That is a real, meaningful difference in what ends up owed over a long delay, and this tool does not model compounding.
No. A late fee is a contractual charge for paying past the due date. It is not a substitute for an actual collections process, and charging one does not by itself recover an invoice that a customer has no intention of paying.
That's a business and relationship decision this tool can't answer for you. A high rate maximizes what a single overdue invoice could theoretically collect, but it can also affect a customer relationship you may want to keep. What rate to actually set and when to enforce it is a judgment call, not something a calculator can make for you.
Next
Upstream reads real per-order cost, real per-SKU landed cost, and real per-order shipping straight from your store, and nets ad spend and returns against it too. It is the connected calculator this page's arithmetic is a two-minute version of.