New Excel add-in

Understand any Excel model
you didn't build.

FormulaMapper is a Microsoft Excel ribbon add-in that reads any workbook you open and answers the questions that take an analyst hours: what does this formula do, what's broken, where are the hidden hardcodes, how clean is this model? - every answer ties back to a cell, so it's auditable, not a black box.

Try it free for 15 days

Pop in your email and we'll send the download link + the 3-step install. Full features for 15 days, then a one-time license. Windows & Mac.

~460 KB .xlam~2.5 MB .exe installerExcel 2016+Mac Excel 16+ No spam · unsubscribe anytime.
Explain
Review Formula
Plain English
Trace
Understand
Onboard
Sheet Map
Contents
Check
Risks
Hardcodes
Score
The Formula Mapper ribbon tab in Excel
Built for the people handed a model they didn't build - FP&A inheritors, deal & audit reviewers, anyone who has to understand and sign off on someone else's spreadsheet. You don't need an enterprise license or a sales call.
Group 1 · Explain Read any formula and trace where its numbers come from.
Ctrl+Q

Review Formula

Pops up the active cell's formula and an expandable precedent tree. Each node shows its live value and role; click to highlight that fragment and jump to the source cell, and the formula bar follows you as you go deeper. Drill into a reference to see its formula - and when a range mixes formulas, every distinct one is surfaced so nothing hides.

Why it matters: stop scrolling a 5-level-deep formula by hand.

Workbook.xlsx · D14 · =VLOOKUP(B14,Pricing!$A$2:$E$200,5,FALSE)*Units
=VLOOKUP(B14, Pricing!$A$2:$E$200, 5, FALSE) * Units
↳ VLOOKUP lookup
↳ Pricing!E47 value: 12.50
↳ Units value: 240
= 3,000.00 final
Plain English

Plain-English Explain

Describes the active cell's formula as a plain-English sentence - exactly what you want when you inherit a model and stare at =IFERROR(VLOOKUP(MATCH(…))) for the first time. Rule-based and offline; nothing leaves your machine.

Why it matters: understand a cryptic formula in seconds, not minutes.

G22 · Plain-English Explain
=IFERROR(VLOOKUP(MATCH($A22, Lookup!$B:$B, 0), Refs!$A:$Z, COLUMN(), 0), "")
Plain English
Find $A22 in the Lookup table's column B. Use that row to pull the matching value from the Refs table in the same column position. If anything fails, leave the cell blank.
Dependents

Trace Dependents + Ask AI

Shows which cells depend on the active cell - across all sheets - as a tree, so you can see the blast radius before you change a number. Optional Ask AI sends only the formula text and structure, never your data.

Why it matters: know what breaks downstream before you edit.

Inputs!B7 · Trace Dependents (3 sheets, 7 cells)
Inputs!B7 root
↳ Calc!D12 = B7 * 1.18
↳ Calc!D14 = SUM(D12:D13)
↳ Output!B5 = Calc!D14 * Multiplier
↳ Output!B9 = B5 / Months leaf
Group 2 · Understand Get the shape of a whole workbook fast.
The hero feature

Onboarding Brief

For a workbook you didn't build: one click produces a plain-English brief covering what the model does, its key outputs, the calculation drivers, a suggested sheet read-order, and the riskiest cells. It turns "where do I even start?" into a guided tour.

Why it matters: no incumbent does this - it owns the inheritance job.

FY26 Forecast.xlsx · Onboarding Brief
Purpose: Bottom-up revenue + cost forecast across 3 product lines for FY26.
Inputs → Drivers → Outputs flow on sheets: InputsCalcSummary
Read order: 1. Inputs (16 rows) → 2. Pricing → 3. Calc → 4. Summary
Top risks: 3 circular refs in Calc!K12:K14, 47 hardcodes in Pricing
Action: review hardcodes before trusting outputs in Summary
Structure

Sheet Map + Contents

Renders how the workbook's sheets reference each other as a colour-coded node diagram - hover or click a sheet to light up its relationships. And generates a hyperlinked index of every sheet, named range, and table.

Why it matters: see the architecture before you trust the numbers.

Workbook structure · 6 sheets, 14 cross-refs
Inputs
Pricing
Refs
Calc hub
Forecast
Summary output
Performance

Calc Timing + Object Links

Ranks sheets by recalculation time to find the bottlenecks slowing the model down. And lists which cells feed charts, pivots, data validation, form controls, and conditional formatting - the hidden wiring that breaks silently.

Why it matters: find the slow sheet and the off-screen dependencies.

Calc Timing · slowest sheets first
Forecast 8,420 ms ⚠
Calc 1,180 ms
Summary 340 ms
Pricing 28 ms
Inputs 3 ms
Group 3 · Check Catch the errors before they reach a client or lender.
One panel

Risk Dashboard

Scans the active sheet and lists every quality issue in one panel - circular refs, errors traced to their origin, inconsistencies, hardcodes, broken external links, volatiles, SUM-gaps and sign checks - sorted worst-first. Click any issue to jump to the cell and highlight it.

Why it matters: findings live in the workbook and drive action - not a detached PDF.

Risk Dashboard · 14 issues found, sorted severity
CRITICAL · Circular ref: Calc!K12 ↔ Calc!K14
CRITICAL · #REF! origin: Summary!B9 (broken after Refs sheet edit)
WARN · 47 hardcoded numbers in Pricing!E2:E48
WARN · Inconsistent formula: Calc!D14 (1 cell differs from 23 others)
INFO · 3 volatile NOW() calls slowing recalc
Hidden risk

Find Hardcodes + Inconsistencies

Flags numeric literals (other than 0 or 1) buried inside formulas - the silent overrides that wreck a model. And flags cells whose formula breaks the pattern of their row or column neighbours, so a stray hand-edit can't hide in a block.

Why it matters: the costliest errors are the ones that look fine.

Pricing!E2:E48 · 47 hardcodes detected
Pricing!E2 = 12.50 hardcode
Pricing!E3 = 14.75 hardcode
Pricing!E4 = 18.20 hardcode
Calc!D14 = =SUM(D12:D13)*1.18 inconsistent: minority pattern
Suggestion: extract magic number 1.18 to Inputs!GST_Rate
Behaviour + hygiene

Stress Test + Compliance Score

Perturbs each input (0, negative, blank, ×10, sign-swap) and reports which outputs break, error, or go negative - automating "save a copy and see what moves." And scores the sheet 0–100 against FAST/SMART-style modelling standards with a grade and concrete recommendations.

Why it matters: checks behaviour, not just structure - the costliest error class.

Stress Test · Inputs!B7 perturbed ±10%, ±25%
Inputs!B7 = 100 → Output!B9 = 3,000 (baseline)
+10% → 3,300 +10%
−10% → 2,700 −10%
+25% → #DIV/0! breaks at +25%
Sensitivity: 1.0× (linear up to ±22%)
Share

Export HTML Report

Writes a self-contained HTML quality report next to the workbook and opens it. Shareable with reviewers, auditors, or your team without sending the original file - handy when the model itself is confidential.

Why it matters: a tidy, sendable artifact for sign-off and review.

Sheet Report · FY26-Forecast.html exported
Compliance Score: 78/100 · FAST-modelling standard
2 critical issues remaining
5 warnings (hardcodes, volatiles)
7 info items (recommendations)
Each row links to the cell in Excel
✓ Shareable HTML, no data leaves your machine

Simple, fair pricing

Prices shown for

Explore

Free
No license needed
  • Precedent tree (Ctrl+Q)
  • Trace dependents
  • Sheet Map & Contents
  • Plain-English Explain
Download free
Most popular

Pro

- one-time
Own it forever · 1 year of updates
  • Everything in Explore
  • Onboarding Brief · Stress Test · Snapshot
  • Risk Dashboard & Compliance Score
  • Compare Versions · hardcode/inconsistency scans
  • Review notes & HTML reports
Start 15-day free trial

Team / Audit

- per machine
Volume discounts for 5+
  • Everything in Pro
  • Sign-off coverage export
  • Bulk key issuance
  • Priority support
Talk to us
Prices are auto-localized to your region (purchasing-power adjusted) - pick another above if you like. Licensed per machine; move it to a new computer any time. 50% off for students & non-profits.

Install in 3 steps

  1. Download FormulaMapper.xlam (~460 KB) above.
  2. Move the file to your Excel add-ins folder: Windows is typically %AppData%\Microsoft\AddIns\, Mac is ~/Library/Group Containers/UBF8T346G9.Office/User Content/Add-Ins/.
  3. Enable in Excel: File → Options → Add-Ins → Manage: Excel Add-ins → Go… → tick FormulaMapper → OK. The Formula Mapper ribbon tab appears.

Blocked? If Excel says the file is blocked, right-click the .xlam → Properties → tick Unblock → re-enable. Standard for add-ins downloaded from the internet. (We're code-signing the installer to remove this step.)