Comparison

Converter vs Roll Length Calc

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

Head to head
About

Converter

This app offers a comprehensive unit and hardness conversion tool with an easy-to-use interface. It includes currency conversion with updated exchange rates, over 300 engineering and scientific units, and a specialized hardness converter. Additional features like timezone conversion, pace calculation, and a standard calculator enhance its utility.

Highlights
  • Currency converter with live exchange rates
  • Over 300 engineering and scientific units
  • Specialized hardness converter
  • Timezone conversion
  • Running pace calculator
  • Integrated standard calculator
  • Conversion history log
Features
Read full description

Trelleborg’s “Unit and Hardness Converter” converts a comprehensive list of units (incl. currencies) in an easy way. In addition, the app has a set of other useful features on board, like timezone conversion, percentage calculations, a running pace calculator and more What our users say: “Have been using it forever, never tried other converter as this one does the job perfectly” - Lazareth_fr “Fabulous resource, but also a functional masterpiece!” -Otto. “This is needed by all engineers. So simple and easy to use” -JLa03.   FEATURES • Easy-to-use interface • Currency converter with in-app exchange rate update functionality • Over 300 engineering and scientific conversion units in 32 categories • Hardness converter with 16 conversion tables based on ASTM E140-07 and ISO-18265 for quick conversion between different scales • Video library: features the extensive Trelleborg Sealing Solutions YouTube library • Toggle between units • Switch between dark and white theme • Conversion history log • Create favorite lists • Standard calculator integrated with unit converter DIMENSIONS • Area • Currency • Current • Data • Density • Distance • Dynamic Viscosity • Energy • Force • Frequency • Kinematic Viscosity • Moment of inertia • Power • Prefixes • Pressure • Speed • Strength • Temperature • Time • Torque • Volume • Weight • Fuel Consumption • Glucose • Vacuum • Numbers • Illumination • Radioactivity • Radiation (absorbed) • Angles • Volume Flow Rate • Calorie • Metric Prefixes • Typography • Electric Charge OTHER MISCELLANEOUS CATEGORIES • Timezone conversion • Clothing sizes / Shoe sizes • International power plugs • Running pace calculator • Percentage calculator • Pace • Hex, Binary, Decimal • BMI (metric/inch) HARDNESS SCALES INCLUDED • Rockwell (HRC, HRA, HRD, HRF, HRG, HRE, HR-15-N, HR-30N, HR-45-N, HR45-T, HR-15T, HR-30T, HR45-T) • Brinell (HBW, HBS) • Vickers (HV, • Knoop (HK) The app is available in English, German and Chinese languages. Download now or contact us with any questions.

About

Roll Length Calc

Calculate the length and area of rolled materials with precision. Save, search, and manage your calculations with detailed reports and notes. Supports multiple units and offers a user-friendly interface for professionals.

Highlights
  • Calculate roll length from diameters and thickness
  • Compute material surface area
  • Save calculations with custom titles and types
  • Add notes to reports
  • Search through saved reports
  • Calculate roll diameter from length
  • Support for multiple units of measurement
Read full description

Roll Length Calc - Accurate Material Calculations Professional app for calculating rolled material length, area and creating detailed reports. MAIN FEATURES: Calculate roll length based on diameters and material thickness Compute material surface area Save calculations with custom titles and material types Add notes to each report Complete list of all saved calculations Search through reports and materials New Feature: Now you can calculate the roll diameter based on the length and material parameters! Just switch modes and get the result instantly. Thanks to your feedback, we keep improving the app. If you find it useful, please leave a review on the App Store – it helps us a lot! Support for multiple units of measurement (mm, cm, m, inches) CREATE COMPREHENSIVE REPORTS: Specify material type (film, fabric, paper, metal) Add detailed notes and comments Maintain complete calculation history Organize and manage your data efficiently PERFECT FOR: Manufacturing companies and factories Construction and engineering firms Logistics and supply chain services Warehouse and inventory management Engineers and technicians Technical students and educators CALCULATION CAPABILITIES: Roll length of various materials Surface area calculations Winding density coefficient Precise mathematical formulas TECHNICAL SPECIFICATIONS: Simple and intuitive user interface Fast and accurate computations Secure data storage and backup Support for metric and imperial systems Optimize your production processes with our advanced calculator. Calculate roll length, generate comprehensive reports, and manage your materials efficiently. Essential tool for professionals working with rolled materials in manufacturing, construction, and logistics industries.

Screenshots

Converter4 screens
Roll Length Calc4 screens

Verdict

The call

The clearest difference is price: Converter at Free against Roll Length Calc's $0.99. On review sentiment, update cadence, ads and in-app purchases 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

Converter is free to download; Roll Length Calc costs $0.99 up front. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

Both ship on a similar rhythm, roughly every 2 months. The most recent releases landed on October 20, 2026 and September 7, 2026 respectively.

Scorecard2 real differences · 8 level
Converter versus Roll Length Calc: the parameters behind the verdict, then further details
ParameterConverterRoll Length Calc
PriceFree — better$0.99
Rating4.9 (980 ratings) — better—
Positive reviews93.9% of reviews100.0% of reviews — better
Number of ratings980 — better—
Update frequencyEvery 2 monthsEvery 2 months
AdsNoNo
In-app purchasesNoNo
MonetizationFree — betterPaid
DevicesiPhone, iPad, iPod — betteriPhone, iPod
Requires iOS15.615.6
Further details — not scored
Size37 MB2 MB
Age rating12+17+
DeveloperTrelleborg Sealing SolutionsKonstantin Khoroshun

Customer experience

Converter

All ratings897 ratings
Positive98.1%
Neutral1.3%
Negative0.6%
Written reviews608 reviews
Positive93.9%
Neutral3.3%
Negative2.8%

Roll Length Calc

Written reviews1 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

Bugs and requests

Converter

Reported bugs

2 issues
  • Occasional crashes on startup for non-English/German users
  • Conversion from meters to feet does not show inches

Requested features

3 requests
  • Add fuel efficiency conversions
  • Allow users to set favorite conversions as default
  • Improve currency conversion rate updates

Roll Length Calc

Not enough reviews yet to summarise bugs or requests.

In-app purchases

None

Converter

No in-app purchases

None

Roll Length Calc

No in-app purchases

Questions

Is Converter free?
Converter is free to download, with no in-app purchases.
Is Roll Length Calc free?
Roll Length Calc costs $0.99, with no in-app purchases.
Do Converter or Roll Length Calc have ads?
Neither Converter nor Roll Length Calc shows ads.
Which is updated more often, Converter or Roll Length Calc?
Converter ships an update every 2 months, and Roll Length Calc every 2 months. Most recently, Converter was updated on October 20, 2026 and Roll Length Calc on September 7, 2026.

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