Telescope Eyepiece Calculator

Magnification & TFOV

Free · In-App Purchases · Designed for iPad

Pick the perfect eyepiece in seconds. Live magnification, TFOV & exit pupil—offline. Now with iPad support, 24 languages, and improved themes. Telescope Eyepiece Calculator is a professional, 100% offline tool for astronomers and serious stargazers. Enter your telescope aperture and focal length, pick an eyepiece (Plössl, Wide, UWA, Hyper, or custom), and instantly see magnification, exit pupil, true field of view (TFOV), and f-ratio: all with a clean, night-friendly design. Why it’s useful • Choose the right eyepiece faster: live results as you type. • Avoid weak or mushy views: color badges warn about over/under magnification and tiny exit pupils. • Plan smarter sessions: see TFOV, power category (Low/Medium/High), and the effect of Barlow/Reducer multipliers. Free Features • Telescope aperture & focal length (mm/inches) • Eyepiece focal length and type presets • Barlow/Reducer support with custom multipliers • Magnification, Exit Pupil, TFOV, f-ratio (real-time) • Power category (Low/Medium/High) • Night Mode + haptic feedback • One Equipment Case (save your default setup) • Works fully offline. No accounts. No tracking. Pro Features (one-time upgrade) • Unlimited Cases: organize multiple telescopes & eyepieces • Side-by-Side Compare: evaluate two eyepieces at once • Precision Field-Stop TFOV: field-stop diameter for ultra-accurate TFOV • Quick Sets: one-tap telescope + Barlow combos • Premium Themes: Glass, AMOLED, Space Gray + adjustable haptics • PDF Export: share a clean session setup card • Smart Hints: color-coded warnings for over/under magnification Built for iPhone and iPad with a crisp interface that’s easy on the eyes at the scope, whether you’re viewing planets, the Moon, or wide-field deep-sky objects.

  • This app has not received enough ratings or reviews to display an overview.

• Full iPad support with a native split layout • Improved themes with clearer previews and polish • 24-language localization for a truly global UI • Refined Settings & Pro screen with region-aware pricing • Better keyboard handling and smoother haptics • Many small UI fixes and performance improvements

The developer, Cederic Schmid, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .

  • Data Not Collected

    The developer does not collect any data from this app.

    Privacy practices may vary based, for example, on the features you use or your age. Learn More

    The developer has not yet indicated which accessibility features this app supports. Learn More

    • Provider
      • Cederic Schmid
    • Size
      • 6.1 MB
    • Category
      • Reference
    • Compatibility
      Requires iOS 18.5 or later.
      • iPhone
        Requires iOS 18.5 or later.
      • iPad
        Requires iPadOS 18.5 or later.
      • Mac
        Requires macOS 15.5 or later and a Mac with Apple M1 chip or later.
      • Apple Vision
        Requires visionOS 2.5 or later.
    • Languages
      English and 22 more
      • English, Arabic, Czech, Danish, Dutch, French, German, Greek, Hebrew, Indonesian, Italian, Japanese, Korean, Norwegian Bokmål, Polish, Portuguese, Simplified Chinese, Spanish, Swedish, Thai, Traditional Chinese, Turkish, Vietnamese
    • Age Rating
      4+
    • In-App Purchases
      Yes
    • Copyright
      • © Cederic Schmid