Входни данни
Calculate and save on one screen
Optional. Internal names are fine.
Match the coefficient basis
Coefficients (a, b)
Confirm source and assumptions (cm TL) before use.
0 < a
1 < b < 5 is typical
Adjust for regional/seasonal variation (guideline)
Additional features
Open only if needed
Estimation helpers
- Recalculates on input changes (button stays, but updates are live)
- Pin saved coefficients at the top
- One-click copy for results
Presets (reference)
Confirm source and assumptions (cm TL) before use.
Japanese horse mackerel (Trachurus japonicus)
a=0.01096, b=2.97 / TL
Chub mackerel (Scomber japonicus)
a=0.00741, b=3.05 / TL
Japanese flounder (Paralichthys olivaceus)
a=0.00794, b=3.07 / TL
Japanese seabass (Lateolabrax japonicus)
a=0.01259, b=3.02 / TL
Red sea bream (Pagrus major)
a=0.01288, b=3.03 / TL
Black seabream (Acanthopagrus schlegelii)
a=0.02138, b=2.99 / TL
Mode A: assume b and solve for a
Estimated a
—
Формула: a = W / L^b
Mode B: fit a,b from multiple data points
| L | W |
|---|
Fit results
Fit with least squares on log(W) = log(a) + b log(L)
Set coefficients at the top. Enable per-row coefficients if needed.
| Species | Дължина | Estimated weight | Range min | Range max | Действия |
|---|
Save & share
Example JSON schema
{
"version": "1.0",
"baseUnits": { "length": "cm", "weight": "g" },
"coefficients": [
{
"id": "myset-001",
"name": "PlantA_RedSeaBream_2026Spring",
"species": { "common": "Red sea bream", "scientific": "Pagrus major" },
"lengthType": "TL",
"a": 0.01288,
"b": 3.03,
"defaultErrorPct": 20,
"source": { "label": "FishBase (Bayesian length-weight)", "url": "https://fishbase.se/Summary/SpeciesSummary.php?id=445&lang=japanese" },
"notes": "Adjust by region/season"
}
]
}
Бележки
- This estimate is a guideline. Results vary widely by region, season, maturity, and measurement type (TL/FL/SL).
- Use coefficients with the same length type and unit basis.
ЧЗВ
I don't know a and b
In the “Unknown coefficients” tab you can (1) back-solve a from one sample with assumed b, or (2) fit a,b from multiple data points.
I want to calculate multiple individuals
Use the “Batch” tab to enter a table or paste CSV. You can download results as CSV.
Can I switch cm/in and g/lb?
Yes. Length and weight units can be switched anytime (internal calculation uses cm and g).
Why is the error large?
Even within a species, weight varies by region, season, body condition, and age. Viewing estimates as a range is recommended.
Свързани инструменти
Length–weight calculator for fish (W=aL^b). Save/share coefficients as JSON.