Floor Vibration Quick Check (18/√δ)
Estimate floor natural frequency straight from its dead-load deflection.
A wonderfully compact identity: gravity ties frequency to static deflection (f = (1/2π)√(g/δ) ≈ 15.76/√δ; 18 reflects typical continuity). 25 mm of sag = a 3.6 Hz trampoline.
Formula
Floor Vibration Quick Check (18/√δ) is a free floor vibration for structural engineers, fabricators and site engineers — instant, accurate and 100% client-side, with the governing formula and reference shown next to the result so the number can be defended, not just quoted.
About Floor Vibration Quick Check (18/√δ)
Estimate floor natural frequency straight from its dead-load deflection. The calculation implements f ≈ 18/√δ (δ in mm) (Wyatt / SCI P354 — vibration design of floors). A wonderfully compact identity: gravity ties frequency to static deflection (f = (1/2π)√(g/δ) ≈ 15.76/√δ; 18 reflects typical continuity). 25 mm of sag = a 3.6 Hz trampoline.
How to use Floor Vibration Quick Check (18/√δ)
- 1Enter Deflection under self-weight + permanent load in mm.
- 2Read Estimated natural frequency instantly — no submit button needed.
- 3Need US units? Flip the SI/Imperial toggle and every field converts.
Why use Floor Vibration Quick Check (18/√δ)?
- ✓Implements the standard formula — f ≈ 18/√δ (δ in mm)
- ✓Reference cited on-page: Wyatt / SCI P354 — vibration design of floors
- ✓One-click SI ⇄ Imperial toggle — values convert in place, physics stays in SI
- ✓Live worked example: the substitution recomputes from your numbers
- ✓Built-in engineering verdict flags out-of-range results instantly
- ✓Runs entirely in your browser — nothing uploaded, free forever
Frequently asked questions
What formula does the Floor Vibration Quick Check (18/√δ) use?+
It computes f ≈ 18/√δ (δ in mm), per Wyatt / SCI P354 — vibration design of floors. The formula is displayed under the result along with a worked example substituted with your own inputs.
What should I keep in mind when using this calculator?+
A wonderfully compact identity: gravity ties frequency to static deflection (f = (1/2π)√(g/δ) ≈ 15.76/√δ; 18 reflects typical continuity). 25 mm of sag = a 3.6 Hz trampoline.
Can I use this for real structural design?+
It implements the exact textbook/code formula cited below the result and is ideal for sizing, checking and learning. Final designs should be verified by a qualified engineer against the full code with all load cases.
Is the Floor Vibration Quick Check (18/√δ) free to use?+
Yes — completely free, no sign-up, no limits. It runs client-side in your browser, so inputs stay private and results are instant even on slow connections.
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