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SwiftSums

82 free calculators.Zero guesswork.

Turn everyday questions into precise, verifiable answers. Every calculation comes complete with the formula, assumptions, and next steps.

Results appear as you type. Try “how much concrete for a slab”, “split a dinner bill”, or “standard deviation”.

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Clear answers.Every source cited.

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Quick access to trusted everyday calculations, with every assumption made clear.

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How does it work?

SwiftSums shows the working behind every answer, so a quick calculation is one you can trust.

  • Type your own numbers — the answer moves as you type.
  • The formula updates with it, using your figures rather than a worked example.
  • Every calculator on the site works this way.
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Tip
Each person pays $33.24 tip $15.21 · total $99.71
Working tip = $84.50 × 18% = $15.21 total = $84.50 + $15.21 = $99.71 each = $99.71 ÷ 3 = $33.24
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