TallyRig: Well Control Calc

New in 1.1: 17 oilfield calculators, faster and cleaner. Kick Tolerance, Kill Sheet, Hydrostatic, Hydraulics, ECD & more — search, arrange, save & share.

17 oilfield & drilling calculators — with a digital tally-book history.

TallyRig is a focused, field-ready calculator set for drilling and well control workflows. Run the essentials fast, save every result, and share a clean record when you need it.

DESIGNED FOR THE RIG • Sunlight Mode: high-contrast screens you can read outside • Glove-friendly: big targets, minimal tapping • Offline-first: works without a signal • Trust the math: review the formula / show-work for each result

17 FIELD CALCULATORS, ORGANIZED BY CATEGORY • Well Control: Kill Sheet (Wait & Weight), Kick Tolerance, Gas Migration, Trip Fill, BOP Check (API Std. 53) • Pressure: Hydrostatic, EMW from Pressure, ECD • Fluids: Mud Weight-Up (barite), Slug, Cementing • Tubulars: Pipe Tally, Buoyancy, Capacity, Stuck Pipe (Free Point) • Hydraulics: Pump Output, Flow, Annular Velocity, Bottoms-Up • Utilities: Oilfield Unit Converter

FIND TOOLS FAST Search, category filters, and a drag-to-arrange dashboard so your most-used calculators are always on top.

HISTORY THAT'S ACTUALLY USEFUL • Save any calculation to a clean history timeline • Share a result card or a history record with your team • Sync across devices via iCloud (when enabled)

UNITS Switch between Imperial and Metric (SI) where supported.

WHO IT'S FOR Drilling engineers, toolpushers, drillers, mud engineers, wellsite supervisors, and well control trainees who want a fast, reliable pocket reference.

IMPORTANT TallyRig is a calculation aid for reference and cross-checking. Always verify inputs and outputs and follow your company procedures and training.