Fly Tying Calculators
Free fly tying calculators for hook sizing, material weight, thread coverage, and pattern scaling.
Essential tools for fly fishers and tiers.
Hook sizing, proportions, materials and tippet matching. 9 calculators for tiers. Rods, reels and open water gear sit under Fishing.
Tippet X ratings are a leftover from drawing gut leaders through plates, where each pass counted as an X. More X means thinner, and the arithmetic is plain: diameter in inches is 0.011 minus X thousandths. The guide’s shortcut is hook size divided by 4, so a size 16 fly takes 4X. Run that backwards from 0X, though, and it asks for hook size zero, which does not exist, because the numbering goes 4, 2, 1 and then jumps to the 1/0 scale. Below about 3X, pick by pound test and fly weight instead.
Hook size carries the same reversal. Numbers count down as hooks get bigger, from a size 28 midge at a 1.5 mm gap to a size 2 pike hook at 12 mm, and then the /0 scale counts back up.
Cost per fly is worth running once. Materials are cheap per fly and alarming per shopping trip.
Fly-Tying Cost Per Fly Calculator
Estimate the materials cost of a single tied fly. Add hook cost plus prorated material costs (thread, hackle, dubbing) to see your true per-fly investment.
Fly-Tying Hackle Size by Hook
Get the recommended hackle feather length for any standard dry fly hook size. Includes both barb length range and gape multiplier rule of thumb.
Fly Tying Bead Head Size Guide
Match tungsten or brass bead head size to your hook size. Get recommended bead diameter, bead weight, and approximate sink rate improvement.
Fly Tying Total Weight Calculator
Estimate finished fly weight in grains from hook size, bead, wire wraps, and dressing. Use for matching fly to leader, sink rate, and presentation.
Fly Tying Thread Wraps Per Inch Calculator
Calculate how many thread wraps cover one inch of fly hook shank by thread denier. Enter thread size and hook length to estimate total wraps needed.
Fly-Tying Proportions Calculator
Calculate standard fly-tying proportions from shank length and gap width. Get tail, body, wing, and hackle dimensions for dry flies, nymphs, and more.
Tippet X-Rating to Pound Test Calculator
Convert tippet X-rating (0X to 8X) to pound test, diameter in mm and inches, and matching fly hook size. Standard fly fishing reference.
Fly Tying Hook Size Calculator
Find the right hook size for any fly pattern from target species and fly type. Covers dry, wet, nymph, streamer, and saltwater hooks with gap guidance.
Fly Tying Material Weight Calculator
Calculate material weights in milligrams and grains for fly tying to hit target sink rate. Returns balanced weights for nymph, streamer, and dry fly patterns.