Estimating Fish Weight From Length Alone. What CT Bass and Striper Communities on Candlewood, Bantam, and the Sound Have Found Works in the Field

The most widely used field-weight formula requires both length and girth:

Weight (lbs) = (Length × Girth²) ÷ 800

Length and girth are both measured in inches.

How to measure girth: Wrap a flexible tape measure around the widest point of the fish, typically just behind the pectoral fins and ahead of the dorsal fin. Anglers fishing Candlewood and Bantam bass tournaments report keeping a soft tape looped around their lanyard for exactly this check.

Example: A largemouth that is 19 inches long with a 14-inch girth: 19 × (14 × 14) ÷ 800 = 19 × 196 ÷ 800 = 3,724 ÷ 800 = 4.65 lbs

The ÷800 divisor was developed for round-bodied species: bass, stripers, trout. Many anglers fishing CT waters find it tracks reasonably well for those fish, though leaner post-spawn bass will typically run lighter than the estimate and fat fall fish often run heavier.

For flatfish like fluke, body shape is different enough that the standard divisor doesn't apply cleanly. Length-girth estimates for fluke carry more uncertainty than they do for round-bodied species, so the fluke figures in the next section should be treated as rougher benchmarks than the bass or trout equivalents.

When girth measurement isn't practical, or when getting the fish back quickly is the priority, CT anglers rely on length-only tables. Fish condition and season both shift actual weight, sometimes by a meaningful margin, so treat all figures as directional estimates.

Largemouth Bass:

• 12 inches ≈ 0.8 lbs
• 15 inches ≈ 1.5 lbs
• 18 inches ≈ 3.0 lbs
• 20 inches ≈ 4.0 lbs
• 22 inches ≈ 5.5 lbs
• 24 inches ≈ 7.0 lbs

CT DEEP enforces a 12-inch minimum size limit on most inland bass waters. The 12-inch figure is included here as a slot reference, not a suggested target.

Striped Bass:

• 18 inches ≈ 1.5 lbs
• 24 inches ≈ 4.0 lbs
• 28 inches ≈ 7.0 lbs
• 32 inches ≈ 10 lbs
• 36 inches ≈ 14 lbs
• 40 inches ≈ 18–22 lbs (lean spring fish on the Sound often run toward the lower end; heavy fall fish toward the upper)

Rainbow Trout:

• 12 inches ≈ 0.6 lbs
• 15 inches ≈ 1.2 lbs
• 18 inches ≈ 2.5 lbs
• 20 inches ≈ 3.5 lbs

CT DEEP stocks rainbow trout annually in the Farmington, Willimantic, Salmon River, and dozens of other waters. Stocked fish often run leaner than wild fish of the same length, particularly in early spring before they've had time to put on condition.

Fluke (Summer Flounder):

• 16 inches ≈ 1.5 lbs
• 19 inches ≈ 3.0 lbs
• 22 inches ≈ 5.0 lbs

These figures are drawn from community-reported field observations among CT Sound anglers fishing Niantic Bay, the mouth of the Thames, and the offshore rips. Given that the standard length-girth formula doesn't transfer cleanly to flatfish body shape, treat fluke estimates as rough benchmarks rather than close calculations.

Bump board for bass: A bump board lets you measure quickly with the fish barely out of the water. Place the tail against the zero end, read the nose position with mouth closed. Bass tournament circuits on Candlewood and Bantam typically require this method, and anglers who fish those events are practiced at it.

Closed-mouth standard: Standard practice for bass and most freshwater species is mouth closed, tail compressed to its longest natural point for total length.

CT striper measurement and regulations: CT DEEP Marine Fisheries sets the official measurement standard for striped bass, and those requirements can change between seasons. Before using any length estimate for a compliance decision on a borderline fish, verify the current method directly from the CT DEEP Marine Fisheries annual regulations summary. The stakes on a questionable striper are high enough that a community table is not the right reference.

C&R handling and CT DEEP guidelines: CT DEEP publishes catch-and-release best practices for regulated species. The approach CT bass and striper communities consistently apply is to minimize time out of the water. On catch-and-release events at Candlewood and Bantam, experienced anglers report targeting sub-30-second handling from net to release, and a practiced length read from a bump board is how they hit that window without reaching for a scale.

Building your eye over time: Anglers who have worked through a large number of fish against a marked bump board report developing a reliable visual sense for weight ranges. That skill is useful for quick in-water estimates when keeping the fish submerged entirely is the goal.