Free BPM to LFO Rate Calculator

How to Use This LFO Rate Calculator

Set your BPM using the slider, number box, or tap tempo, and the table updates instantly with the LFO rate in Hz for every common note value — straight, dotted, and triplet. Tap any value to copy it, then paste it directly into your synth's LFO rate field if it accepts Hz. If your plugin instead has a "sync" dropdown with note values (1/4, 1/8T, 1/16D, and so on), you don't need the Hz number at all — just pick the matching note value on the dropdown and skip the manual entry entirely.

Unique Feature: Voice Feedback

Turn on Voice Feedback and tap a value to hear the Hz number read aloud — useful when you're working on a hardware synth across the room from your laptop and don't want to keep walking back to check a screen.

Why Sync an LFO to Tempo

An LFO (low-frequency oscillator) that isn't locked to your track's BPM will drift in and out of phase with the beat — a filter sweep, tremolo, or auto-pan effect that sounded perfectly rhythmic at the start of a loop slowly falls out of sync as the bars go by. Syncing the LFO rate to a note value at your project tempo keeps that movement locked to the groove permanently, no matter how long the section plays. Most modern synths offer a tempo-sync toggle that handles this automatically once you pick a note division, but plenty of hardware, older plugins, and Eurorack modules only accept a raw Hz number — that's exactly the gap this calculator fills.

The Math, in Case You Want It

A quarter note's LFO rate in Hz is simply your BPM divided by 60 — at 120 BPM that's 2 Hz, meaning the LFO completes two full cycles every second. Every other note value scales from there: a half note is half that frequency (slower), an eighth note is double (faster), and so on. Dotted values multiply the base rate by 2/3, while triplets multiply by 3/2, which is the opposite direction from how those ratios work for note duration in milliseconds — worth remembering if you're used to the delay-time version of this math, since LFO rate and delay time are inversely related.

Where This Shows Up in Real Production

Trance and progressive house lean heavily on tempo-synced filter LFOs for that classic rising-and-falling "riser" sound under a pad or lead. Dubstep and bass music use fast, synced LFOs on a wobble bass to get the wub-wub rhythm locked exactly to the groove rather than sounding loose. Tremolo effects on guitar or keys — that pulsing volume effect — sound far more musical synced to a note value than left at a fixed, untempo-related Hz setting. Even something as simple as an auto-pan effect on a synth pad reads as intentional rather than accidental once it's locked to the beat.

Synth-Specific Notes

Serum and Vital both have a tempo-sync toggle right on the LFO panel — flip it on and you get a note-value dropdown instead of a raw Hz knob, so you'll rarely need to type in a Hz number directly in either. Ableton's native LFO devices (and most Max for Live tools) work the same way. Where this calculator actually earns its keep is with hardware synths, older plugins without a sync option, and Eurorack LFO modules, which frequently only expose a Hz or millisecond parameter with no built-in tempo awareness at all.

Who Actually Needs This

Sound designers building patches for hardware or Eurorack are the main crowd, since that's where tempo sync usually just doesn't exist as a built-in option — you're stuck reading a Hz value off a knob and hoping it lines up. Producers working with older or budget plugins that skipped a sync feature run into the same wall. And even with modern synced synths, some producers deliberately want an LFO rate that's a specific fraction off from the beat for a slow phasing effect, which means dialing in a precise Hz number rather than picking from a preset note-value list.

A Common Mixup Worth Avoiding

People sometimes assume a "faster" LFO means a longer note value, since that's backwards from how note duration works — a whole note is the longest duration, but here it produces the slowest, lowest-Hz rate, while a thirty-second note produces the fastest, highest-Hz rate. If a synced effect sounds way too fast or way too slow compared to what you expected, double-check you haven't picked the note value that's the inverse of what you meant.

LFO Rate at a Glance (120 BPM Reference)

Frequently Asked Questions

How do I calculate LFO rate from BPM? Divide your BPM by 60 to get the Hz rate for a quarter note. For other note values, multiply or divide that number based on the ratio between the note value and a quarter note.

What LFO rate is a dotted eighth note at 120 BPM? A straight eighth note at 120 BPM is 4 Hz; a dotted eighth is two-thirds of that rate, roughly 2.67 Hz. Use the table above for any BPM instantly.

Does my synth need tempo sync, or can I just enter Hz manually? If your synth has a tempo-sync toggle with note-value options, use that instead — it'll stay locked even if you change the project BPM later. Manual Hz entry is really for gear that doesn't offer sync at all.

Is LFO rate math the same as delay time math? They use the same BPM-based foundation, but Hz and milliseconds are inversely related — faster rates mean shorter durations. Our Delay Time Calculator handles the millisecond side if that's what you need instead.