RigMaster vs RigCalcPro

RigMaster is the rigging calculator built for working riggers, crane operators, and signal persons. LIFT PLAN PDF (PRO) • Turn any calculation into a one-page lift plan: diagram, inputs, results • Room for notes and three signature lines — prepared by, signature, date • Share it straight to the supervisor from the toolbar IPAD & UNITS • Universal app — two-column layout on iPad, any orientation • Metric or imperial — kg and metres or lb and feet, switch any time • Live sling diagram with the angle and tension on every leg FREE CALCULATORS • Sling Tension — 2-leg picks by angle, or by sling length & height (the way you actually measure) • Hitch Capacity — vertical, choker, and basket capacity from YOUR sling's tag rating • Angle Reference — the tension multiplier table, always in your pocket PRO CALCULATORS • 3 & 4-leg bridles with rigid/flexible load sharing • Unequal Legs / CoG Offset — tension per leg when the center of gravity isn't centered • Load Weight Estimator — steel, concrete, aluminum and more, by shape and dimensions • Ad-free Built on first-principles trigonometry with warnings at 45° and hard alerts below 30°, following standard rigging practice (ASME B30.9 guidance). RigMaster is an estimation aid for qualified riggers. Always follow the sling tag, the load chart, and your site's rigging plan. COMMON QUESTIONS Does it work offline? Yes. Every calculation runs on the phone. No signal needed on site. Do I need an account? No. There is no login and no sign-up. What is free? Sling Tension, Hitch Capacity and the Angle Reference table are free. Pro adds 3 and 4-leg bridles, unequal legs with CoG offset, the load weight estimator and the lift plan PDF, and removes the ads. Metric or imperial? Both, switchable at any time — kg and metres, or lb and feet. Can I hand the result to the supervisor? Yes. Pro turns any calculation into a one-page lift plan PDF: diagram, inputs, results, notes and three signature lines. Does it replace the sling tag or the load chart? No. It is an estimation aid for qualified riggers. The sling tag, the load chart and your site's rigging plan always come first. Does it work on iPad? Yes. Universal app, two-column layout on iPad, any orientation. Terms of Use: https://ghapps1.wordpress.com/terms-condition/ Privacy Policy: https://ghapps1.wordpress.com/privacy-policy/

RigCalc Pro turns your iPhone into a complete rigging calculator for every rigger, crane operator, and lift supervisor in the field — 100% offline, no signal required. Get accurate sling tensions, load weights, and capacity checks before the load leaves the ground — all in one app, with no brand lock-in. Stop guessing your rigging. Whether you're calculating sling leg tension at a tight angle, estimating the weight of a steel plate, finding the center of gravity of an asymmetric load, or checking crane capacity against the load chart, RigCalc Pro delivers the numbers you need to plan a safe lift. RIGGING CALCULATORS: - Sling Load Calculator — Leg tension for 1 to 4 leg slings. Enter the sling angle directly or let the app compute it from height and length. Instant warnings when angles drop below 30 degrees and tensions multiply. - Load Weight Estimator (Premium) — Estimate load weight from shape and material. Plates, pipes, cylinders, blocks, and I-beams in steel, aluminum, concrete, wood, and more. - Center of Gravity Calculator (Premium) — Two-point lifts on asymmetric loads. Get the share of load at each pick point and the CoG position before you rig. - Crane Capacity Check (Premium) — Load weight plus rigging weight plus hook block against chart capacity. See utilization percentage and safety status at a glance. - Drift / Headroom Calculator (Premium) — Hook height and sling lengths in, clearance above the load out. Know your headroom before the lift, not during it. REFERENCE GUIDES: - Shackle WLL Chart — Working load limits by shackle size for screw pin anchor shackles. - Wire Rope Sling Capacity — Capacities by rope diameter and hitch: vertical, choker, and basket. - Chain Sling Capacity — Grade 80 and Grade 100 chain by leg count and sling angle. - Web Sling Capacity — Synthetic web sling capacities for every common hitch. - Eyebolt Capacity — Rated loads with angle reduction factors. - Crane Hand Signals — Illustrated guide to standard crane hand signals. - Hitch Types Guide — Visual reference for vertical, choker, and basket hitches. - Unit Converter — Tons, pounds, kilograms, feet, meters, and more. YOUR DATA, YOUR WAY: - Calculation History — Every calculation is saved automatically. Review and compare past results. - 100% Offline — No internet required. Every calculation runs on-device. Use it on the deck, in the yard, or on remote sites with zero connectivity. - Dark Mode — Designed for bright outdoor glare and low-light night shifts. FREE vs PREMIUM: Free includes the Sling Load Calculator, crane hand signals, hitch types guide, unit converter, and calculation history. Premium unlocks the Load Weight Estimator, Center of Gravity, Crane Capacity Check, and Drift/Headroom calculators, all capacity reference charts, and every future calculator and reference tool as they are added. IMPORTANT SAFETY NOTICE: RigCalc Pro is a planning aid for trained and qualified rigging personnel. All values are for reference only — always verify capacities with the manufacturer's tag and current ASME B30 / OSHA 1926.251 requirements before lifting. Never exceed rated capacities. SUBSCRIPTION Premium requires a paid auto-renewing subscription: US$1.99 per week (with a 1-week free trial) or US$19.99 per year (with a 1-month free trial). When the free trial ends, the subscription renews automatically and your Apple Account is charged, unless you cancel at least 24 hours before the current period ends. You can manage or cancel your subscription in your Apple Account settings. Terms of Use (EULA): https://rigcalcpro.volvoxmobile.com/rigcalcpro/terms Privacy Policy: https://rigcalcpro.volvoxmobile.com/rigcalcpro/privacy