Free catch-and-release tool
Baja Saltwater Fish Weight Calculator
Release first. Estimate the weight afterward.
Cabo Sportfishing Magazine offers this free calculator to support catch and release in Baja. If you can take a quick measurement safely, release the fish and enter its length afterward. If measuring would delay the release, skip it.
Fish Weight Calculator
Release first. Estimate the weight afterward. If measuring would delay the release, skip it.
Monthly fishing reports
November 2026
October 2026
September 2026
April 2026
Length-to-weight charts
Each chart is drawn from the same published equation as the calculator, across each model’s stated length limits. These limits can represent a study sample or reference-chart coverage, as disclosed below. These are estimates, not scale weights: two fish of the same length can weigh differently depending on condition, season and recent feeding.
Snout to tail fork · Range 5.2–133 cm · Source
Snout to tail fork · Range 33–149 cm · Source
Tip of lower jaw to tail fork · Range 150–290 cm · Source
Rear edge of left eye orbit to tail fork · Range 109–269 cm · Source
Rear edge of left eye orbit to tail fork · Range 95–279 cm · Source
Snout to tail fork · Range 59–169 cm · Source
The 59–169 cm span describes the overall study sample, not the confirmed range of the 442 fish used for the weight fit.
Total length, snout to tail tip · Range 21–55 cm · Source
Total length, snout to tail tip · Range 21–59 cm · Source
Snout to tail fork · Range 20–170 cm · Source
The 20–170 cm limit is the span of the NOAA reference chart, not the original sample range. · NOAA yellowfin length–weight reference chart
Snout to tail fork · Range 80–190 cm · Source
The 80–190 cm limits are documented in the ICCAT literature review, which marks this entry as a secondary citation; the original 1966 sample table has not been independently inspected. The calculator and chart use only that reported span, not a guaranteed accuracy interval. · Carroceda & Colmenero (2016), ICCAT 72(2):472–484, Table 6, p. 481 — bigeye sample range (secondary citation)
Snout to tail fork · Range 39–71 cm · Source
Rear edge of left eye orbit to tail fork · Range 124–196 cm · Source
Sources and method
The calculator applies the published length–weight relationship W = a × L^b for each species, with length converted to centimeters and weight returned in kilograms and pounds. Estimates are shown only inside each model’s stated limits. Bigeye tuna uses the 80–190 cm span reported for its exact equation in ICCAT’s literature review; its secondary-source qualification remains beside the result.
- NOAA Fishery Bulletin, Ortega-García et al., roosterfish length–weight relationship — Baja California Sur. Sexes-combined coefficients for Baja California Sur. Specimens above 100 cm were scarce in the study.
- Ortega-García et al. (2018), Latin American Journal of Aquatic Research 46(1), Table 1, pooled-sex dorado model — Los Cabos, Baja California Sur. Pooled-sex model. The methods label the output in grams, but the table’s coefficients are consistent with its reported kilogram weights; this implementation uses the kilogram interpretation. Estimate labeled provisional pending author confirmation of the source units.
- IOTC 2014 WPB12, Table 2, round-weight length–weight equations — Taiwanese offshore and coastal fisheries. IOTC round-weight model; this is not a Cabo-calibrated equation.
- IOTC 2014 WPB12, Table 2, round-weight length–weight equations — Central North Pacific research. IOTC round-weight model; this is not a Cabo-calibrated equation.
- IOTC 2014 WPB12, Table 2, round-weight length–weight equations — Central North Pacific research. IOTC round-weight model; this is not a Cabo-calibrated equation.
- Western and Central Pacific wahoo length–weight study, pooled sexes — Western and Central Pacific. Pooled-sex model. The source coefficient of 0.003 for grams is already converted to kilograms here. The 59–169 cm span describes the overall study sample, not the confirmed range of the 442 fish used for the weight fit.
- Santa Rosalía, Baja California Sur snapper length–weight study, abstract coefficients — Santa Rosalía, Baja California Sur. Approximate coefficients reported in the study abstract for this species. Approximate model from rounded study coefficients.
- Santa Rosalía, Baja California Sur snapper length–weight study, abstract coefficients — Santa Rosalía, Baja California Sur. Approximate coefficients reported in the study abstract for this species. Approximate model from rounded study coefficients.
- IATTC whole-weight length–weight equations for yellowfin and bigeye tuna · NOAA yellowfin length–weight reference chart — IATTC whole-weight equation, Eastern Pacific fisheries. IATTC whole-weight equation. The 20–170 cm limit is the span of the NOAA reference chart, not the original sample range.
- IATTC whole-weight length–weight equations for yellowfin and bigeye tuna · Carroceda & Colmenero (2016), ICCAT 72(2):472–484, Table 6, p. 481 — bigeye sample range (secondary citation) — Central Pacific study; equation also used by IATTC for Eastern Pacific assessments. Nakamura & Uchiyama (1966) whole-weight equation: W (kg) = 0.00003661 × fork length (cm)^2.90182, reproduced by IATTC SAC-07-04a, p. 4. ICCAT’s Carroceda & Colmenero (2016), Table 6, p. 481, reports 9,144 Central Pacific fish and an 80–190 cm fork-length span for this exact equation. Not calibrated for Cabo. The 80–190 cm limits are documented in the ICCAT literature review, which marks this entry as a secondary citation; the original 1966 sample table has not been independently inspected. The calculator and chart use only that reported span, not a guaranteed accuracy interval.
- Chatwin (1959) Eastern Pacific skipjack equation, reproduced in FAO Table 2 — Eastern Pacific. Chatwin (1959) Eastern Pacific equation, as reproduced in FAO Table 2.
- Ortega-García et al. (2018), Latin American Journal of Aquatic Research 46(1), Table 1, pooled-sex sailfish model · NOAA observer field manual, p. 55, billfish eye-orbit landmark (includes sailfish) — Los Cabos. Pooled-sex model from 650 sailfish sampled off Cabo San Lucas (1990–2015). The source specifies eye-fork length but not the orbit edge; NOAA’s billfish field manual supplies the posterior margin of the left eye orbit. Table 1 reports kilogram weights, while the methods call W grams; this tool uses the kilogram interpretation provisionally. Estimate labeled provisional pending author confirmation of the source units.
12 species are enabled above. Dorado and sailfish remain provisional; both snapper models are approximate. Bigeye’s chart uses the published review’s 80–190 cm span, with the secondary-source qualification disclosed.