Why is Excel slow on an M-chip Mac?
Short answer: Excel runs slowly on M-chip MacBooks (M1, M2, M3, M4) for three main reasons: the installed version is an old Intel build running through Rosetta 2 (Apple's Intel-to-ARM translation layer — a compatibility bridge that runs Intel-compiled software on Apple Silicon), causing unnecessary overhead; automatic recalculation is enabled and the workbook has complex formulas across many cells; or third-party add-ins are running Intel-only code that imposes Rosetta translation on every add-in call. Fixing the first two resolves most slow-Excel complaints on M-chip Macs within minutes.
How to fix Excel running slow on M-chip Mac
Step 1: Confirm Excel is running as ARM-native, not Intel
Open Activity Monitor (Finder → Applications → Utilities → Activity Monitor), find Microsoft Excel in the process list, and look at the "Kind" column. If it says "Intel," Excel is running under Rosetta 2 and is not using the M-chip's full performance potential. To fix this: open the Microsoft AutoUpdate tool (Help menu in any Office app → Check for Updates) and install all available updates. Microsoft released the ARM-native build of Excel for Mac (version 16.54) in late 2021 and has continued optimising it for M2, M3, and M4. The ARM-native Excel is typically 2–3x faster than the Rosetta version on the same M-chip Mac for formula-heavy workbooks.
Step 2: Switch to manual calculation for large workbooks
Excel recalculates all formulas every time you make any change to a cell, by default. On a workbook with thousands of interdependent formulas — common in financial models and data analysis sheets — this automatic recalculation triggers on every keystroke and causes the spinning beachball. Switch to Manual Calculation: in Excel, click the Formulas menu → Calculation Options → Manual. Now formulas only recalculate when you press Command+= (or the Calculate Now button). Press it when you need current results. Switching back to Automatic when the work session is complete ensures the file is always accurate when saved or shared. This change alone eliminates the beachball for most heavy-workbook users.
Step 3: Disable Intel-only third-party add-ins
Go to Excel → Tools menu → Excel Add-ins. Check how many add-ins are enabled. Third-party add-ins built for Intel Excel (many Indian financial reporting and GST tools fall into this category) force the entire Excel process to use Rosetta when active, even if Excel itself is ARM-native. Disable all add-ins you are not actively using. Test Excel performance after disabling — if performance improves dramatically, re-enable add-ins one at a time to identify which one is the culprit. Contact the add-in vendor for an M-chip-compatible (ARM) version, which many Indian software vendors began shipping after 2023. Our macOS spinning beachball fix guide covers application-level performance optimisations that apply alongside Excel-specific fixes.
Step 4: The India angle — large GST, accounting, and financial Excel files
India-specific Excel heavy usage patterns — GST return preparation, CA firm financial models, banking data exports with tens of thousands of rows — are particularly likely to trigger M-chip Excel slowness because these workbooks were often built on Windows Excel over many years and have accumulated complex formula chains, extensive conditional formatting, and legacy VBA macros. VBA (Visual Basic for Applications — Excel's built-in scripting language) on Mac runs through its own compatibility layer and is noticeably slower than on Windows regardless of chip generation. For large VBA-heavy workbooks, consider converting macros to more modern JavaScript-based Office Scripts, or use Power Query (Get Data) to handle large data transformations more efficiently. An 8 GB M-chip Mac can run a 100,000-row Excel workbook comfortably with no other apps open, but memory pressure increases with each additional app.
When to call a laptop repair service
When DIY ends
Software fixes won't help if: the Mac's available RAM is consistently at capacity (Activity Monitor shows sustained red Memory Pressure with multiple apps open); if the SSD is nearly full (less than 10 GB free — macOS cannot create virtual memory swap files, making all apps slower); or if Excel crashes with an error rather than just running slowly (may indicate a corrupted Office installation needing a full reinstall). The macOS kernel_task high CPU fix can address background system processes competing with Excel for resources.
Typical cost in India
macOS software optimisation at a service centre: ₹800–₹1,500. SSD upgrade if storage is the bottleneck: ₹3,500–₹8,000 for Apple-compatible NVMe on Intel MacBooks (M-chip MacBooks have soldered storage and cannot be upgraded). Microsoft 365 subscription (required for latest Office builds): ₹4,900/year for personal plan, or ₹6,550/year for family.
A note from the LRW Engineer Team
The M-chip MacBook is genuinely fast for Excel — when running the ARM-native version with sensible calculation settings. The most common scenario we see in India is a MacBook Air M2 that still has an Intel version of Office installed (because the user migrated from an old MacBook without running Microsoft AutoUpdate), running a complex CA-firm financial model with hundreds of volatile functions and auto-calc on. Two changes — updating to the ARM-native build and switching to manual calculation — transform the experience from barely usable to fluid. These are five-minute fixes that make a dramatic difference.