# Drill Calc > Calculates drill bit sizes for threaded holes and provides drill bit and pipe data. (iPhone/iPad app by Black Cat Systems.) - Source: https://appshunter.io/ios/app/drill-calc/id304434324 (this page in markdown: same URL + `.md`) - Developer: [Black Cat Systems](https://appshunter.io/developer/301047032) - Category: Utilities, Reference - Price: $2.99 - Rating: 4.10/5 from 19 App Store ratings · 12 written reviews indexed - Age rating: 4+ - Requires: iOS 12.0 · 5 MB - Languages: American English - Released: 2009-02-10 - Data updated: 2026-08-12 - Monetization: paid - User reviews in markdown: https://appshunter.io/ios/app/drill-calc/id304434324/reviews.md ## What is Drill Calc? Need to find the right drill bit size for a hole? Drill Calc calculates the correct drill bit size to use for threaded holes, based on the bolt (tap) diameter and thread pitch and percentage, for both inch and metric threads. Close and tight fit hole sizes for many popular drill sizes are also displayed. It also has tables of standard inch fractional and numeric drill bit sizes, as well as complete information for various pipe sizes. There is also detailed information about the commonly used sizes of wood screws. Buy your copy of Drill Calc today, and put away your drill chart. ## Key features - Calculates drill bit size for threaded holes - Supports inch and metric threads - Displays close and tight fit hole sizes - Includes standard inch fractional and numeric drill bit tables - Provides pipe size information - Offers data on common wood screw sizes ## Recent user reviews (10 of 12) All indexed reviews: https://appshunter.io/ios/app/drill-calc/id304434324/reviews.md ### 5/5 — Handy tool *2026-06-16* First place I look when I have a question about drill or tap size ### 4/5 — Good, but could be better *2026-05-02* I am a hobbyist machinist. I am always using Drill Calc for looking up drill sizes when I am threading. One feature I would appreciate is an all encompassing decimal lookup chart. This single chart would contain fractional, lettered, numbered and metric drill sizes. I also would find it helpful if you supplied the data for doing external threading. ### 1/5 — App fail to load *2024-02-02* I was unable to access the app after downloading it. Restarting my phone did not repair it. Money wasted. ### 4/5 — Value for money *2019-02-13* Great for 99% of threads metric or imperial. Metric could have a few more of the common pitches listed. A seperate group for BSP threads of both US and UK types would be great. ### 5/5 — Awesome *2015-09-02* This app puts at my fingers all the data I could ever need in the machine shop when tapping time comes around. Very detailed and accurate. ### 5/5 — Drill Tap *2014-04-15* Excellent Reference... ### 4/5 — Good, but could be better *2012-11-10* I am a hobbyist machinist. I am always using Drill Calc for looking up drill sizes when I am threading. One feature I would appreciate is an all encompassing decimal lookup chart. This single chart would contain fractional, lettered, numbered and metric drill sizes. I also would find it helpful if you supplied the data for doing external threading. ### 5/5 — V 2.0 works great & w/Pipe Thd data *2010-09-15* This is great; all the Inch - Metric and Pipe Information in one app. We deal with both english and metric taps at the machine shop I work for, so this makes it a very handy app. ### 4/5 — Works well *2009-12-01* Functionality of app is great! Good clean layout. I agree that pipe theads would be a great addition, as well as fine threads for metric taps. Clearance drills, counterbores, and reamer drill sizes would also be a welcomed upgrade. I would pay extra for those options even. Keep up the good work ### 4/5 — Works fine *2009-05-30* It is a plain ol' drill chart, and it works just fine. Thanks! Would like to have pipe threads too, though. ## Frequently asked questions about Drill Calc ### What is Drill Calc used for? Drill Calc is a utility app designed to calculate the correct drill bit size needed for creating threaded holes. It assists users in determining the appropriate bit for both inch and metric threads based on bolt diameter, thread pitch, and desired fit. ### What types of threads does Drill Calc support? Drill Calc supports calculations for both inch and metric threads. This allows for versatile use across a wide range of projects and materials. ### Does Drill Calc offer information beyond drill bit calculations? Yes, Drill Calc includes tables of standard inch fractional and numeric drill bit sizes. It also provides comprehensive information for various pipe sizes and details on commonly used wood screw sizes. ### What is the price of Drill Calc? Drill Calc is available for a one-time purchase of $2.99. This price grants you access to all its features without any recurring fees or in-app purchases. ### On which devices can I use Drill Calc? Drill Calc is compatible with iPhones and iPads. It is designed for iOS devices, allowing users to access its functionality on their Apple mobile devices. ### How often is Drill Calc updated? The latest version of Drill Calc is 2.5, and it was last updated on November 22, 2024. This indicates regular maintenance and potential feature additions by the developer. ### What is the age rating for Drill Calc? Drill Calc has an age rating of 4+, meaning it is suitable for users of all ages. This rating suggests the app's content is appropriate for a general audience. ### Does Drill Calc have ads? No, Drill Calc does not contain advertisements. As a paid application, it offers an ad-free experience for its users. ## Version history (last 5 releases) ### 2.5 — 2024-11-22 Updates for latest iOS versions ### 2.4 — 2016-08-03 This app has been updated by Apple to display the Apple Watch app icon. Added information for wood screws. Combined list of numeric and fractional drill sizes. Updates for iOS 9.3. ### 2.3 — 2013-11-21 Updates for iOS 7 Fixed bugs that could cause a crash ### 2.2 — 2013-01-08 Added close fit and tight fit hole sizes Updates for iOS 6 and the iPhone 5 ### 2.1.0 — 2012-01-04 Corrected spelling errors. ## Apps similar to Drill Calc | App | Rating | Price | Category | | --- | --- | --- | --- | | [Construction Calculator Civil](https://appshunter.io/ios/app/construction-calculator-civil/id6450211084) | — | $5.99 | Utilities | | [Thread Calculators](https://appshunter.io/ios/app/thread-calculators/id1670586227) | 5.0 (1) | $1.99 | Utilities | | [Transition Layouts](https://appshunter.io/ios/app/transition-layouts/id1490428137) | — | $2.99 | Utilities | | [Fluid Mechanics Calculator](https://appshunter.io/ios/app/fluid-mechanics-calculator/id526974981) | 4.5 (21) | $2.99 | Utilities | | [USB Sharp Pro](https://appshunter.io/ios/app/usb-sharp-pro/id436590784) | 3.9 (12) | $2.99 | Utilities | | [OpoLua](https://appshunter.io/ios/app/opolua/id1604029880) | — | Free | Utilities | ## More apps by Black Cat Systems - [WireCalc](https://appshunter.io/ios/app/wirecalc/id301047029) - [Transmission Line Calc](https://appshunter.io/ios/app/transmission-line-calc/id302734281) - [RF Link Calc](https://appshunter.io/ios/app/rf-link-calc/id303034300) - [dB Calc](https://appshunter.io/ios/app/db-calc/id303470503) - [Photon Calc](https://appshunter.io/ios/app/photon-calc/id304436071) All apps by Black Cat Systems: https://appshunter.io/developer/301047032 --- *Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-12.*