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Add exactly half of the straight duration
A dotted note calculator can be independent of tempo when the straight-note time is already known. Enter that duration, and this page adds one half of it. The resulting single-dotted value is three halves of the original.
This route intentionally handles one dot. It does not silently extend the pattern to double- or triple-dotted notation, and it does not infer the note label or BPM behind the number.
The 3:2 relationship
A written dot adds half the duration of the note immediately before it:
added portion = straight duration ÷ 2.
single-dotted total = straight duration + added portion = straight duration × 3/2.
The reverse check multiplies the dotted total by 2/3 to recover the original. Showing both directions helps catch a value that was already dotted before entry.
Worked 240-millisecond example
Enter 240 milliseconds. Half of 240 is 120 milliseconds. Adding that portion produces a dotted duration of 360 milliseconds, or 0.36 seconds.
The reciprocal timing rate is approximately 2.777778 cycles per second. If the optional label says “eighth note,” the copied result can read “straight eighth 240 ms; added dot 120 ms; dotted eighth 360 ms.”
The label affects communication, not arithmetic.
What the dot does not mean
A dot does not add a fixed number of milliseconds. Its contribution scales with the original note. A 200-millisecond straight duration gains 100 milliseconds, while an 800-millisecond duration gains 400.
It also does not mean “add the next smaller named note” unless that name is exactly half the original duration under the same tempo. The ratio is the reliable definition.
Avoid applying the multiplier twice
If a source already gives “375 ms dotted eighth,” entering 375 as though it were the straight eighth produces 562.5 ms, which is not the intended conversion. Use the reverse card first: 375 × 2/3 = 250 ms straight.
Record whether the input is straight or dotted before transferring values between tools or devices.
Relationship to tempo
The page does not ask for BPM. If you know only tempo and a note name, use the note-duration route, which derives the straight value from a declared beat unit before applying the dot.
Keeping the two workflows separate prevents an already calculated millisecond input from being forced through another tempo convention.
Dotted timing in compound meter
A dotted quarter commonly serves as the felt pulse in meters such as 6/8, but notation context does not change the 3:2 rule. A dotted quarter always lasts one quarter plus one eighth under the same time scale.
Whether it represents one conducted beat, an accent group, a delay division, or an LFO cycle depends on context that this numeric converter cannot inspect.
Double dots are outside this action
A second dot adds half the first dot’s addition, or one quarter of the original note, making a double-dotted total 7/4 of the straight value. That is a valid relationship, but it is not the selected single-dot result on this page.
The exclusion keeps the CTA unambiguous and avoids presenting several notation modes under one keyword without sufficient explanation.
Precision and transfer
The addition is calculated before visible rounding. If the straight input came from a rounded display, the dotted result inherits that limitation. Preserve the entered value, unit, ratio, and optional note label.
For a destination that works in integer samples, convert the final dotted duration at its sample rate rather than rounding milliseconds prematurely.
No notation or sound processing
The page does not engrave a score, validate ties, play a click, hear audio, or set an effect. It cannot decide whether dotted rhythm is musically appropriate. It applies one declared duration ratio.
Values remain in page memory and disappear on reset or ordinary navigation. No saved list is created.
Proportional visual check
The result rail shows the dotted addition as a second segment half the length of the straight segment. Together they occupy three equal half-segments. If a copied or manually entered total does not preserve that proportion, review the source unit and decimal separator.
For a reverse task, divide the dotted total into three equal parts and combine two. A 900-ms dotted value becomes three 300-ms parts; two parts recover a 600-ms straight value. This geometric check reaches the same 2/3 reverse formula without relying on a memorized decimal multiplier.
Frequently asked questions
What is the dotted form of 500 milliseconds?
The added half is 250 ms, so the single-dotted total is 750 ms.
Why multiply by 1.5?
One full original plus one half equals one and one-half, or 3/2.
Can I enter seconds?
Yes. The page normalizes the unit and reports both seconds and milliseconds.
Does the calculator support two dots?
No. The interaction is deliberately limited to the single-dotted 3:2 relation.
Enter the known straight time, inspect the added half, and copy the ratio-labeled dotted result.