About the Delay and Reverb Calculator
This tool computes two of the most common time-based settings in audio production. First, it converts a song's tempo (BPM) and a chosen note division into a delay time — in both milliseconds and Hz — so an echo, ping-pong delay, or modulation effect can lock to the beat. Second, it estimates a room's reverberation time (RT60), the time for sound to decay by 60 dB, using the Sabine equation from room volume, surface area, and an average absorption coefficient.
The tempo-synced delay formula
A quarter note at a given tempo lasts 60000 ÷ BPM milliseconds. Every other note value is a fixed multiple of that quarter note:
- Whole note ×4, half note ×2, dotted half ×3
- Quarter note ×1, dotted quarter ×1.5, quarter triplet ×2/3
- Eighth note ×0.5, dotted eighth ×0.75, eighth triplet ×1/3
- Sixteenth note ×0.25
Multiply the quarter-note length by the chosen multiplier to get the delay time in milliseconds. The equivalent rate in Hz is 1000 ÷ delay time (ms) — useful when a plugin asks for a modulation rate instead of a millisecond value.
The Sabine reverb time formula
Reverberation time is estimated with the Sabine equation, published by physicist Wallace Clement Sabine in 1898 and still the standard first-pass model in architectural acoustics:
RT60 = 0.161 × V ÷ A
where V is the room volume in cubic meters and A is the total absorption in metric sabins, calculated here as total surface area (m²) multiplied by an average absorption coefficient (α, a unitless value from 0 to 1). A higher α means more sound-absorbing surfaces — carpet, curtains, or acoustic foam — and a shorter, drier decay; a lower α (hard tile, glass, bare concrete) means a longer, more reflective decay.
Why the two numbers are compared
Mix engineers frequently check a synced delay's repeat time against the room or reverb plugin's RT60 to keep the two effects from smearing together. If the delay time is a small fraction of RT60, the echoes tend to sit inside the reverb wash rather than stand out. If the delay time is a large fraction of RT60, distinct rhythmic echoes ring out past the reverb tail. This calculator reports that ratio as a quick sanity check — it is a mixing convention, not a fixed rule, and the right balance always depends on the material and the desired effect.
Frequently Asked Questions
How is a tempo-synced delay time calculated?
What is the Sabine equation for reverb time?
Why do the delay time and reverb time get compared?
Does the Sabine equation work for every room?
Common Tip Percentages
| Service | Typical Tip Range | Notes |
|---|---|---|
| Restaurant (sit-down) | 15–20% | 20%+ for exceptional service |
| Food delivery | 10–20% | Consider extra for long distances |
| Taxi / rideshare | 10–20% | More for assistance with luggage |
| Hotel housekeeping | $2–5/night | Leave daily, not just at checkout |
| Barber / hair salon | 15–20% | On pre-discount total |
| Pizza delivery | 10–15% or $3–5 minimum | Higher in bad weather |
General Household Budget Ratios (50/30/20 Rule)
| Category | % of Net Income | Examples |
|---|---|---|
| Needs | 50% | Rent, groceries, utilities, insurance |
| Wants | 30% | Dining out, entertainment, hobbies |
| Savings / Debt | 20% | Emergency fund, retirement, extra payments |
Common Measurement Conversions for Everyday Use
| Quantity | US / Imperial | Metric Equivalent |
|---|---|---|
| 1 cup | 8 fl oz | 237 mL |
| 1 pint | 16 fl oz | 473 mL |
| 1 quart | 32 fl oz | 946 mL |
| 1 gallon | 128 fl oz | 3.785 L |
| 1 lb | 16 oz | 453.6 g |
| 1 ft | 12 in | 30.48 cm |