Rainfall Calculator vs Thetis Tools
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
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.
- Instant rainwater calculation
- Cost savings evaluation
- Minimum tank size recommendation
- Supports various input units
- Formula references included
- Results copyable to other apps
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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.
Thetis Tools
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Applicazione Ufficiale per la piattaforma di asta live Thetis Tramite questa applicazione i clienti thetis possono trasmettere in diretta live il video della propria sessione d'asta all'applicativo asta live Thetis
Screenshots
Verdict
The clearest difference is price: Thetis Tools at Free against Rainfall Calculator's $2.99. Thetis Tools also leads on update cadence (every 7 months vs every 29 months). Rainfall Calculator's advantage is chart position (#176 vs unranked). On ads, in-app purchases, device support and iOS requirement 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
Thetis Tools is free to download; Rainfall Calculator costs $2.99 up front. Neither carries in-app purchases, so what you see is what you pay.
Rainfall Calculator ships an update every 29 months, Thetis Tools every 7 months. The most recent releases landed on September 9, 2026 and September 10, 2026 respectively.
| Parameter | Rainfall Calculator | Thetis Tools |
|---|---|---|
| Price | $2.99 | Free — better |
| Rating | 5.0 (1 ratings) — better | — |
| Number of ratings | 1 — better | — |
| Update frequency | Every 29 months | Every 7 months — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | — |
| Best chart rank | #176 — better | — |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 13 — better | 14.0 |
| Further details — not scored | ||
| Size | 1 MB | 50 MB |
| Age rating | 4+ | 4+ |
| Developer | Nitrio | Thetis srl |
In-app purchases
Rainfall Calculator
No in-app purchases
Thetis Tools
No in-app purchases








