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Compare anything.
Never miss a due date.

Dueter puts two things side by side and turns payment terms into exact dates. Fast, private tools that work right in your browser.

Calculate a due date Explore all tools
  • Nothing stored
  • Instant results
  • Free forever
The duet

Two versions. Every difference.

Line them up, scan once, and see exactly what changed. That is the idea behind every Dueter compare tool.

Two glass documents slide into alignment while a scan line highlights the rows that differ.
  • Side by sideBoth versions in one view
  • Changes highlightedNo more squinting at two tabs
  • Stays on your deviceBuilt to run in your browser
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When is that invoice actually due?

Pick a date and a payment term. The answer updates as you go.

Payment due Saturday, 7 November 2026 30 days from the invoice date
Open the full calculator

Weekend rules, early payment discounts and custom terms are in the full calculator.

The toolkit

Small tools, done properly

One focused job per tool, with a clear answer and a plain guide behind it.

See every tool
Why Dueter

Built like a product, free like a utility

Private by design

The maths runs in your browser. We never store, log or sell what you type.

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Instant

Results update as you type. No spinners.

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Sign-ups

Open a tool and use it. That is it.

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Term types

Net, EOM, MFI, discounts and custom days.

Checked against the rules

Month ends, leap years and weekend rules are all tested against worked examples.

Stop guessing dates.
Start knowing them.

Free tools for deadlines and side-by-side checks. No account, no limits.

Try the calculator