Comparison

Plumbing Formulator vs YearViewer

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Plumbing Formulator

This professional calculator app provides over 200 formulas, calculators, and reference materials for plumbers, HVAC technicians, and mechanical contractors. It covers a wide range of calculations for water flow, piping, drainage, water heaters, pumps, and more, all in one pocket-sized tool.

Highlights
  • Over 200 formulas and calculators
  • Water flow and supply calculations
  • Pipe and piping calculations
  • Drainage and venting calculations
  • Water heater and pump calculations
  • Reference charts and code books
  • Pipe cut list optimizer
Features
Read full description

PLUMBING FORMULATOR is the ultimate professional calculator for plumbers, HVAC techs, and mechanical contractors. Over 200 formulas, reference charts, code books, and pro tools in your pocket. CALCULATORS AND FORMULAS Water Flow and Supply: pipe velocity, flow rate, GPM, fixture unit demand, and supply sizing. Pipes and Piping: area, volume, and weight for copper, steel, cast iron, and plastic. Hazen-Williams friction loss, pressure ratings, and 45 degree offsets. Drainage and Venting: drain sizing, slope and fall, vent sizing, fixture units, and wet vents. Water Heaters: BTU requirements, recovery rates, tank sizing, first hour ratings, and hot water demand. Pumps and Pressure: water and brake horsepower, efficiency, head pressure, velocity head, and PSI to feet of head. Storm Drainage: roof drains, rainfall intensity, gutter and leader sizing, and retention. Gas Piping: size natural gas and propane lines, BTU loads, pressure drop, and appliance demand. Medical Gas: size oxygen, nitrogen, nitrous oxide, and medical air. Vacuum demand and manifolds per NFPA 99. Swimming Pools: volume, fill time, pump sizing, turnover, evaporation loss, and main drains. Septic and Sewage: septic tanks, leach fields, and sewage pump capacity. Thermal Expansion: expansion tank sizing, system pressure, and pipe length changes. REFERENCE MATERIALS Charts and Tables: dozens of reference charts including pipe sizing, fixture units, and materials in PDF. Massachusetts Plumbing Code: complete 248 CMR reference with all chapters. Plumbing Design Guide: a 24 chapter design and installation guide. Technical Drawings: professional diagrams and installation details. TOOLS AND FEATURES Pipe Cut List Optimizer: enter lengths and stock sizes for an optimized cutting plan that cuts waste. Unit Conversions: length, area, volume, flow, pressure, temperature, weight, and power. Geometry Calculators: area and volume for circles, rectangles, triangles, cylinders, spheres, cones, and more. BUSINESS MANAGEMENT More than a calculator. Tap Business to run your service company from the same app. Customers: contacts, service addresses, job history, and outstanding balances. More than a calculator. Tap Business to run your service company from the same app. Customers: contacts, service addresses, job history, and outstanding balances. Quotes and Estimates: build quotes on site and turn an approved quote into an invoice with one tap. Invoicing: branded invoices with your logo, parts and labor, taxes, and terms. Send by email, print, or PDF. Payments: cash, check, card, ACH, or credit. Apply one payment across invoices and manage credit automatically. Scheduling: book service calls, track jobs, and set up recurring contracts that auto-generate invoices. Business Reports: balances, receivable aging, revenue, and payment history. Export as CSV or PDF. Business features are a separate one-time upgrade, discounted for existing Bill-Craft and ServiceBoss customers. PLUMBING PRO FEATURES Upgrade to Plumbing Pro to save calculations with full detail, export results, keep unlimited history, and remove ads. One time purchase with lifetime access. A modern dark interface built for the job site, with breakdowns showing the steps and formulas behind every result. Perfect for plumbers, apprentices, HVAC techs, mechanical engineers, and building inspectors. Download Plumbing Formulator today and put professional plumbing calculations at your fingertips.

About

YearViewer

View a calendar overview for any year, past or future. Customize your view with optional week numbers, adjustable start days, and different week layouts. Pinch to zoom and use device settings for language.

Highlights
  • Yearly calendar overview
  • Select any past or future year
  • Optional week numbers (ISO 8601)
  • Customizable first day of the week
  • Pinch-to-zoom functionality
  • Device language integration
Features
Read full description

This app shows an overview calendar for any year. It shows the months, the days of the week, and (optionally) the week numbers. When you start the app it shows the current year, but the "time machine" button allows you to select any year in the past or future. Features: - Use pinch gestures and double-tap to zoom - The names of the months and days follow the "international" settings of your device - The "time machine" button lets you jump to any year - Weeknumbers (as defined by the ISO 8601 standard) can be shown or hidden - Choose the first day of the week: Sunday, Monday, or any other day - The current day is shown highlighted - The layout of the calendar adjusts itself to the orientation of the device (portrait / landscape) - Choose between different week layouts

Screenshots

Plumbing Formulator4 screens
YearViewer3 screens

Verdict

The call

The clearest difference is review sentiment: YearViewer at 67% against Plumbing Formulator's 9%. YearViewer also leads on in-app purchases (none vs 4) and rating (5.0 vs 4.6). Plumbing Formulator's advantage is update cadence (every 2 months vs every 5 months) and ratings volume (7 vs 2). On price, ads, monetization model and device support there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Plumbing Formulator sells 4 one-off in-app purchases. YearViewer asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

YearViewer holds the better App Store score, 5.0 against 4.6. Both are backed by a comparable volume of ratings — 7 and 2 respectively. Written reviews point the same way: 9% of Plumbing Formulator's written reviews are positive against 67% of YearViewer's.

UpkeepUpdate frequency

Plumbing Formulator ships an update every 2 months, YearViewer every 5 months. The most recent releases landed on October 30, 2026 and October 14, 2026 respectively.

Scorecard6 real differences · 4 level
Plumbing Formulator versus YearViewer: the parameters behind the verdict, then further details
ParameterPlumbing FormulatorYearViewer
PriceFreeFree
Rating4.6 (7 ratings)5.0 (2 ratings) — better
Positive reviews9.1% of reviews66.7% of reviews — better
Number of ratings7 — better2
Update frequencyEvery 2 months — betterEvery 5 months
AdsNoNo
In-app purchasesYesNo — better
MonetizationFreeFree
DevicesiPhone, iPadiPhone, iPod
Requires iOS18.68.0 — better
Further details — not scored
Size123 MB1 MB
Age rating4+4+
DeveloperHistorycentral.comGerard Putter

Customer experience

Plumbing Formulator

All ratings7 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews11 reviews
Positive9.1%
Neutral0.0%
Negative90.9%

YearViewer

All ratings2 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews6 reviews
Positive66.7%
Neutral16.7%
Negative16.7%

In-app purchases

4 purchases

Plumbing Formulator

One-time4
  • Pro Version$1.99
  • Pro Purchase$3.99
  • Starter$5.99
Show 1 more
  • Growth$9.99
None

YearViewer

No in-app purchases

Questions

Is Plumbing Formulator free?
Plumbing Formulator is free to download, with in-app purchases available.
Is YearViewer free?
YearViewer is free to download, with no in-app purchases.
Which has better reviews, Plumbing Formulator or YearViewer?
YearViewer is rated higher. Plumbing Formulator averages 4.6 out of 5 from 7 ratings, while YearViewer averages 5.0 from 2 ratings.
Do Plumbing Formulator or YearViewer have ads?
Neither Plumbing Formulator nor YearViewer shows ads.
Which is updated more often, Plumbing Formulator or YearViewer?
Plumbing Formulator ships an update every 2 months, and YearViewer every 5 months. Most recently, Plumbing Formulator was updated on October 30, 2026 and YearViewer on October 14, 2026.

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