TallyRig: Well Control Calc

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

4 focused calculators

Kill Sheet (Wait & Weight) — key well control outputs (e.g., KMW)

Stuck Pipe — Free Point & Stretch

BOP Check — quick checks aligned to API Std. 53 workflows

Cementing — Volume & Sacks

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.

By using this app, you agree to the Apple Standard EULA:
https://www.apple.com/legal/internet-services/itunes/dev/stdeula/