Duct Calculator
35
Quality Score
Emerging
✍️ Bumetric analysis
“
Duct Calculator is an Android app from LetsFab in the Education category, currently rated 2.6★ across 78 ratings. Initial signal reads as largely positive sentiment, users highlighting consistency and feature depth.
Quality Score is 35: Emerging (early traction worth watching). For a Education app, that means early traction worth watching. The full BU Investment Matrix below scores 8 dimensions including monetisation, growth, and operational risk.
Track changes month-over-month in the Performance section below: live snapshot history and revenue forecast included.
💰 Monthly revenue · now vs forecast
● Right now
$500
per month
→
12-mo forecast
$437 – $1575
per month
→
24-mo forecast
$405 – $3644
per month
INDIE tier
💡 Grow this revenue
Free AI audit of this app’s store listing
- Title & subtitle keyword fit
- Description hook & conversion structure
- Screenshots, ratings, reviews strategy
Typical impact: +2-5× organic installs
📊 Performance Tracking LIVE
1 snapshots on record
Rating
2.6
Reviews
78 reviews
Forecast Revenue / mo
$500
Snapshots tracked
1
since Jun 2026
ONE-TIME · BUILD
💰 Estimated build cost
$140K
↳ What it cost to build · not monthly revenue
Likely range $105K – $190K
$25K · MVP floor
$100K · indie scale
$500K+ · studio build
📈
Slow ROI — current MRR is well below build cost
Synthetic estimate. Inputs: category complexity, file size, screen count, monetization layer, platform reach, age × team-size proxy. Calibrated against 2024-2026 indie-agency rate surveys. Full math + source list on /methodology.
Where the money goes
| 🧱 MVP baseline (design + 1-store ship) | +$28K |
| 📱 5 unique screens × $4.5K | +$22K |
| ⚙ Education complexity ×1.20 | +$10K |
| 🌐 Cross-platform reach (iOS + Android) | +$33K |
| ⚙ 7.8y maintenance × ~1-person team | +$46K |
Total estimate
$140K
ONE-TIME · EXIT VALUE
💵 Estimated acquisition value
$5K
↳ What it would sell for · not monthly revenue
Marketplace range $5K – $10K · 14× MRR multiple
💸
~0.0× build cost (under-water)
Synthetic estimate. Multiple band derived from ad-supported + age, rating quality, category demand, and user-base maturity. Calibrated against 2024-2026 indie-app-marketplace closed-deal medians. Full math + comparable deal list on /methodology.
How the multiple was built
| 📺 Ad-supported base | 15× MRR |
| 📅 7.8y proven track record | +20% |
| ⭐ ★ rating < 3.5 (weak) | -18% |
| 🏷 Education category multiple | +6% |
| ⭐ Small user base (<1K ratings) | -8% |
Final multiple
14× MRR
🛠 Estimated tech stack
🤖
Native Android (Kotlin)
High confidence · 80%
Also possible
Flutter
Heuristic guess from app bundle size, category, store description signals, and release-date stack era. Bumetric does not disassemble binaries — for binary-level certainty you would need an SDK intelligence tool or the manifest itself. Reasoning chain on the right. Full ruleset on /methodology.
Signals we read
| 🏷 Category context | Education |
| 📦 Compact Android bundle | → Native Kotlin |
💀 Maintenance status
Likely abandoned
82%
Last shipped 2025-08-11 · 447 days ago
0 · Active
50 · At risk
100 · Abandoned
Heuristic risk score from time-since-last-update + ratings velocity proxy + Editor's Choice / curated featuring signals. Calibrated against 2024-2025 app-store ranking decay reports. Not a guarantee — a quiet app with a healthy codebase looks the same as an abandoned one until something breaks. Full math on /methodology.
Risk signals
| 📅 1y 2mo since last update | Likely deprioritized |
| 👥 Small user base (78 ratings) + 7.8y old | +10% (solo-project pattern) |
Verdict
Likely abandoned
🔬
How we forecast this revenue
LOW CONFIDENCEBaseline
$500/mo · ML-estimated from 234 triggers
Growth rate
+6.0% MoM · INDIE tier baseline (compound monthly)
Direction
Headwinds: rating drift may slow acquisition
6 months
$426 – $993
12 months
$437 – $1.6K
24 months
$405 – $3.6K
Compound growth at +6.0% MoM (tier baseline for INDIE). Range widens with horizon — typical noise band ±40% at 6mo.. Ranges widen with horizon — distant futures carry more uncertainty.
📊
BU Investment Matrix
Pre-traction · 36/100INDIE TIERlimited signalGrowth Velocity
5.0
Founder Strength
6.0
Product Quality
2.1
Revenue Strength
2.7
Monetization Maturity
1.0
Defensibility
7.0
Market Position
0.0
Operational Safety
5.0
- 💰 Revenue: Marginal — $200 - $1250/mo · INDIE tier · medium confidence, trajectory unclear.
- ⭐ Quality: 2.58★ across 78 reviews — weak — significant quality concerns.
- 📍 Market: Not yet charting in any of the 9 monitored markets.
- 📈 Growth: ⚠ last update 445d ago — possibly dormant.
- ⚠️ Risk: Elevated — dormant (445d since update).
🎯 For competitors: Vulnerable. Quality drift + slow updates create a clear opening for a fresh competitor with active dev cadence.
💵 For acquirers: Estimated asking range 18-32× monthly = $9K-$16K. Portfolio play ($2K/mo combined) commands premium.
Composite of 8 dimensions computed deterministically from public signals — no LLM, every score traces back to a measurable input. Default weights shown; "compete" / "acquire" / "invest" lenses re-weight without re-fetching.
Range:
💰 Forecast Revenue / mo
MODELRevenue forecast computed from BU's 234 trigger model on each snapshot. Calibrated against ground-truth from 58 verified-revenue apps.
🔬Forecast Breakdown — Why This Estimate?Top 4 of 4 triggers
Our ML model uses 200+ signals from public data. These are the most influential for this app:
| Below-average rating (2.6★)METRIC | −$1,500 | |
| Established app (7y old)METRIC | +$800 | |
| Ad-supported / freemiumMETRIC | +$600 | |
| Pre-traction phase (78 ratings)METRIC | −$300 |
METRIC = structural app data · REVIEW = mined from user reviews · ✓ VERIFIED = Stripe-verified anchor (TrustMRR)
📈 Reviews Growth
LIVECumulative review count from first BU snapshot. Each point = a tracked update.
⭐ Rating Trend
LIVEAverage rating evolution. Updates with each new review batch.
Profile & Insights
Everything we know — and don't — about this app and its company.
Identification
- App name
- Duct Calculator
- Developer
- LetsFab
- Bundle ID
- com.pinjara_imran5290.Duct_Calculator
- App Store URL
- Open in App Store
- Category
- Education
- Content rating
- Not found
- Languages
- Not found
Company
- Website
- www.letsfab.in
- Tagline
- Not found
- Description
- Not found
- Founded
- Not found
- HQ / Address
- Not found
- Employees
- Not found
- Logo
- Not found
Revenue
- Reported revenue signal / mo
- Not found
- AI revenue estimate / mo
- Not found
- AI annual estimate
- Not found
- Model estimate / mo
- $500/mo
- Top-grossing rank
- Not found
- All-time revenue
- Not found
- Pricing
- Not found
Founder
Founder data not yet collected for this app.
Funding
Funding data not yet collected for this app.
Press & Links
Press & Links data not yet collected for this app.
Contacts & Socials
Contacts & Socials data not yet collected for this app.
Profile is built from iTunes Lookup + developer site scrape + ML revenue model. Empty fields show "Not found" — additional sources (Crunchbase, X, IndieHackers, Acquire.com) coming.
📝 About this app
This app is developed to Calculate Duct Size Required with available CFM & FPM.
This app calculate Both Rectangular and Round Duct Sizes in Inches.
This App is also Calculate Air Flow rate in CFM and this app is also calculate in Air Velocity in FPM.
The application is designed for engineers HVAC working in the field of design and installation of ventilation systems.
Heating, ventilation, and air conditioning (HVAC) engineers and designers will find this tool to be valuable in their everyday design and construction work
This app calculate Both Rectangular and Round Duct Sizes in Inches.
This App is also Calculate Air Flow rate in CFM and this app is also calculate in Air Velocity in FPM.
The application is designed for engineers HVAC working in the field of design and installation of ventilation systems.
Heating, ventilation, and air conditioning (HVAC) engineers and designers will find this tool to be valuable in their everyday design and construction work
App Specs
🔐 Own this app? Claim & verify MRR →🔖 v8.0.0🔄 updated 1y ago📂 Education💰 Free📺 Ad-supported🚀 Launched 2019 (7y old)
🔔
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📝 Description
95
BU Score · Transcendent
More by LetsFab
View all →📦 Portfolio summaryINDIE studio
88apps·$71K/mocombined
✓ Diversified — top app contributes 7%; risk spread across portfolio
About this analysis
Why low confidence: only 78 ratings · no founder-verified revenue (model estimate only) · revenue figure is directional only.
❓ Frequently Asked Questions
9 answers · auto-generated from this app's public dataHow much does Duct Calculator make per month?▴
Based on our ML-calibrated revenue forecast, Duct Calculator earns approximately $500/mo. This is a US-storefront-equivalent estimate; global revenue can be several times larger for internationally-distributed apps. See the methodology page for the full formula and confidence bands.
Is Duct Calculator profitable?▴
With estimated build cost $140K and monthly revenue $500, Duct Calculator looks well below break-even — current monthly revenue is much smaller than the estimated build cost. Profitability also depends on paid-acquisition spend and refund rate which the public model doesn't see.
What apps are like Duct Calculator?▴
Browse the full Education category catalog to find similar apps with revenue, build cost, audience and tech stack data. Each /p/{slug} page also shows a Compare side-by-side widget with three peer apps from the same niche.
What is Duct Calculator built with?▴
Our heuristic places Duct Calculator on the Native Android (Kotlin) stack (High confidence, 80%). Signals: app bundle size, category context, store-description markers, release-date era. We don't disassemble binaries. Alternative possibilities: Flutter.
Is Duct Calculator still actively maintained?▴
Maintenance status: Likely abandoned (82% abandonment risk). Last shipped version was 1+ years ago. The risk score combines time-since-last-update with Editor's Choice / curated featuring + user-base maturity adjustments.
How much would Duct Calculator sell for?▴
Estimated acquisition value: $5.0K (marketplace range $5.0K – $10K). Calculated as 14× monthly revenue using the standard multiple for the detected monetization model + adjustments for age, rating quality and category demand. Calibrated against 2024-2026 Flippa / Acquire.com / MicroAcquire closed-deal medians.
When was Duct Calculator last updated?▴
Duct Calculator last shipped a new version on 2025-08-11 — more than 1 year(s) ago. This is the date Apple / Google last accepted a new build, not a content-only push.
Who makes Duct Calculator?▴
Duct Calculator is published by LetsFab on the Google Play Store. See the full publisher portfolio (other apps by the same developer) via the More by developer block on the product page above.
What is Duct Calculator's BU Score?▴
Duct Calculator has a BU Score of 35/100 (Emerging). The score combines App Store rating, ratings count, monetization model and revenue signals calibrated against founder-verified MRR anchors. See the BU Score formula.