Comparison

Rainfall Calculator vs Paint Calculator Plus

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

Head to head
About

Rainfall Calculator

Calculate potential rainwater harvest volume and cost savings. This tool helps determine annual water collection capacity based on rainfall and roof area, recommending optimal tank sizes for efficient water storage. It also allows for cost-saving analysis by comparing harvested water to mains water prices.

Highlights
  • Instant rainwater calculation
  • Cost savings evaluation
  • Minimum tank size recommendation
  • Supports various input units
  • Formula references included
  • Results copyable to other apps
Features
Read full description

The Rainfall Calculator is a physics/math tool designed to help you determine how many liters/gallons of rainwater you can harvest per year, evaluate cost savings, and recommend the minimum tank size for water storage. Features: - Instant calculation. - Results can be copied to other apps. - Includes formula references. - Supports up to 16 decimal places. - Supports various units for each input. - Works seamlessly on both iPhone and iPad. - Lightweight, compact app optimized for everyday use. - Ad-free and built with privacy in mind. Rainwater Collection Calculator: - The catchment area is multiplied by the depth of rain that falls on it to give the total volume of water produced. - 1 millimeter of rain over 1 square meter of roof equals 1 liter of water. - Annual rainfall (in millimeters) x Roof surface area (in square meters) = Roof catchment capacity. - You can add the cost of mains or tap water per m³ to evaluate the annual cost savings if this rainwater is collected and used instead of drinking water. - The minimum tank size should store 33% of the "Annual Rainfall On Your Roof Area" as you will use the water while you are collecting it. The rain will collect in gutters that channel the water into downspouts and then into some sort of storage vessel. Rainwater collection systems can be as simple as collecting rain in a rain barrel or as elaborate as harvesting rainwater into large cisterns to supply your entire household demand. You can also collect rainwater for garden use. Plants prefer rainwater because it's naturally soft and free of chlorine and other chemicals. If drought is a problem where you live, collecting rainwater is a good way to handle watering restrictions. If you're on a municipal water system, you can save a considerable amount of money. Thank you for your support! Visit nitrio.com for more apps for your iOS devices.

About

Paint Calculator Plus

Estimate the exact amount of paint and primer needed for any project. Input wall dimensions and exclude areas like doors and windows for precise calculations. Supports metric and imperial units.

Highlights
  • Instant paint calculations
  • Input multiple walls and surfaces
  • Exclude doors, windows, and openings
  • Automatic area calculations
  • Supports metric and imperial units
  • Copy results to other apps
Features
Read full description

Use the Paint Calculator to estimate how much paint and primer you’ll need for your project. Before you buy, use our paint calculator to determine exactly how much paint is required to transform your space. Add up the total square footage if you're painting more than one room with the same color. Features: • Instant calculations • Input multiple walls or surfaces to paint • Input multiple doors, windows, or openings to exclude • Automatic paint area calculation • Automatic excluded area calculation • Wall surface types: very smooth, smooth, common, or rough • Estimate paint and primer usage • Supports both Metric and Imperial systems • Results can be copied to other apps Enter the dimensions of your walls, then enter the dimensions of the areas you don't want to paint, such as windows, doors, or openings. Please Note: These calculations are intended to provide only a rough estimate. Actual paint requirements may vary based on several factors, including application method. Thank you for your support! Visit nitrio.com for more apps for your iOS devices.

Screenshots

Rainfall Calculator4 screens
Paint Calculator Plus4 screens

Verdict

The call

Rainfall Calculator and Paint Calculator Plus are too close to call on the numbers: across 8 compared parameters — price, update cadence, ads and in-app purchases among them — neither pulls far enough ahead to decide it. What separates them is feature set and interface, not measurable difference.

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

Rainfall Calculator costs $2.99 and Paint Calculator Plus $2.99 up front. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

Rainfall Calculator ships an update every 29 months, Paint Calculator Plus every 38 months. The most recent releases landed on September 9, 2026 and July 5, 2026 respectively.

ScorecardNo meaningful differences
Rainfall Calculator versus Paint Calculator Plus: the parameters behind the verdict, then further details
ParameterRainfall CalculatorPaint Calculator Plus
Price$2.99$2.99
Rating5.0 (1 ratings) — better—
Positive reviews—0.0% of reviews
Number of ratings1 — better—
Update frequencyEvery 29 months — betterEvery 38 months
AdsNoNo
In-app purchasesNoNo
MonetizationPaidPaid
Best chart rank#176 — better#200
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS1312.0 — better
Further details — not scored
Size1 MB9 MB
Age rating4+4+
DeveloperNitrioHeng Jia Liang

Customer experience

Rainfall Calculator

All ratings1 ratings
Positive100.0%
Neutral0.0%
Negative0.0%

Paint Calculator Plus

Written reviews1 reviews
Positive0.0%
Neutral0.0%
Negative100.0%

In-app purchases

None

Rainfall Calculator

No in-app purchases

None

Paint Calculator Plus

No in-app purchases

Questions

Is Rainfall Calculator free?
Rainfall Calculator costs $2.99, with no in-app purchases.
Is Paint Calculator Plus free?
Paint Calculator Plus costs $2.99, with no in-app purchases.
Do Rainfall Calculator or Paint Calculator Plus have ads?
Neither Rainfall Calculator nor Paint Calculator Plus shows ads.
Which is updated more often, Rainfall Calculator or Paint Calculator Plus?
Rainfall Calculator ships an update every 29 months, and Paint Calculator Plus every 38 months. Most recently, Rainfall Calculator was updated on September 9, 2026 and Paint Calculator Plus on July 5, 2026.
Which is more popular, Rainfall Calculator or Paint Calculator Plus?
Rainfall Calculator currently peaks at #176 in the App Store charts, and Paint Calculator Plus at #200. Chart position reflects recent download velocity rather than total install base.

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