Best Metric System Apps

250+ iOS apps curated and reviewed

4.4 avg rating

19 free apps

Updated September 2026

Every iPhone needs a few good metric system apps. We benchmark 250+ of them on App Store rating, freshness, and pricing, then surface the standouts so you don't have to scroll the App Store yourself.

Compare top Metric System Apps (September 2026)

#	App	Price	Rating	Ads	In-App Purchases	Updated
1	Metric Conversion tool	Free	4.8★ (15K)	No	No	Sep 2026
2	Unit Converter - Best Unit App	Free	4.8★ (193K)	Yes	Yes	Sep 2026
3	Fraction Calculator	Free	4.7★ (157)	No	Yes	Sep 2026
4	Converter (unit conversions)	Free	4.7★ (1.9K)	No	Yes	Sep 2026
5	High Plains: Measure Metric	Free	—	—	No	Jul 2026
6	Jan sushi	Free	—	No	No	May 2026
7	Unit Converter - Convert all	Free	4.6★ (13K)	Yes	Yes	Sep 2026
8	Shiftz Unit: Global Scale	Free	—	Yes	No	May 2026

Top Picks for Metric System

#1

Metric Conversion tool by Wight Hat

Unit and currency converter

Editor's Choice

4.8😐(15K ratings)

Free

Metric Conversion tool screenshot 1

Metric Conversion tool screenshot 2

Metric Conversion tool screenshot 3

Metric Conversion tool screenshot 4

Metric Conversion tool screenshot 5

This app provides a comprehensive unit and currency converter with a user-friendly interface. It offers offline functionality, supports over 30,000 unit conversions, and includes more than 160 currencies with live exchange rates. Users can save favorite conversions and get precise results.

What We Love

💡 Useful conversion tool
👍 Easy to use and navigate
🚀 Quick and efficient
👍 Comprehensive coverage of conversions

Room to Improve

🔊 Intrusive and loud ads
🔒 Questionable privacy practices
🐛 Inaccurate conversions
👎 Disruptive to workflow

#2

Unit Converter - Best Unit App by Alan Mrvica

Convert All Units and Currency

Strong Contender

4.8😊(193K ratings)

FreeAdsIn-App Purchases

#96in Travel

Unit Converter - Best Unit App screenshot 1

Unit Converter - Best Unit App screenshot 2

Unit Converter - Best Unit App screenshot 3

Unit Converter - Best Unit App screenshot 4

Unit Converter - Best Unit App screenshot 5

Unit Converter - Best Unit App screenshot 6

Easily convert between a wide range of units across 20 categories, including length, weight, temperature, and more. Features live currency updates for 155 world currencies, refreshed daily. Designed for simplicity and visual appeal.

What We Love

🚀 Easy to use
👍 Comprehensive conversions
💡 Useful for travel and cooking
🚀 Quick and efficient
👍 Intuitive interface

Room to Improve

🐛 Limited character input
🐛 Difficulty with negative numbers
💡 Lack of ability to quickly switch between conversions
💰 Pro version not worth the cost

#3

Fraction Calculator by xNeat.com

Decimal Plus Units Converter

Worth Considering

📊 Productivity

4.7😐(157 ratings)

FreeIn-App Purchases

Fraction Calculator screenshot 1

This tool converts between decimals and fractions, and also handles unit conversions for construction and metric measurements. It offers an intuitive interface for calculations and editing, with advanced features available through upgrades.

What We Love

👍 Intuitive and easy-to-use interface
🚀 Fast calculation performance
💡 Excellent for woodworking and construction projects
🎨 Clean, customizable design with multiple themes
📐 Handles fractions beautifully with imperial measurements
⚡ No ads or annoying popups
🔄 Useful backspace function for tweaking calculations
⌚ Available on Apple Watch
🎓 Great educational tool for learning fractions
💾 Minimal storage footprint

Room to Improve

💰 Extremely expensive subscription model
🔐 Paywall blocks most useful features in free version
😞 Recent update changed from free to paid model
🎯 Unclear which features require payment
🖱️ Small buttons prone to accidental clicks
📱 Poor Apple Watch support for fractions
❌ Bait-and-switch monetization strategy
🔄 Confusing fraction input method for some users
⚠️ App functionality degraded in recent updates

More Metric System apps to explore

Converter (unit conversions)

Converter (unit conversions)

Converter (unit conversions)

by Brent Royal-Gordon

Easily convert between 76 measurement units across eight common types, including length, weight, temperature, and volume. Features a built-in calculator and optional currency conversion with daily exchange rate updates.

76 measurement units8 common unit typesBuilt-in four-function calculator

free with in-app purchases

High Plains: Measure Metric

High Plains: Measure Metric

High Plains: Measure Metric

by Prakasa Prasetya

by Viktoriia Muzyria

🍔 Food & Drink

Unit Converter - Convert all

Unit Converter - Convert all

Unit Converter - Convert all

Measurements & Calculations

Easily convert between various units of measurement, including currencies, temperature, length, and weight. This intuitive tool provides real-time currency exchange rates and a comprehensive list of conversions for everyday use.

Real-time currency conversionsExtensive unit categories (weight, temp, length, volume, etc.)Simple and intuitive interface

free with in-app purchases

Shiftz Unit: Global Scale

Shiftz Unit: Global Scale

Shiftz Unit: Global Scale

SpiritBank Mobile Banking

SpiritBank Mobile Banking

SpiritBank Mobile Banking

That's the Spirit!

Manage your finances on the go with this secure mobile banking application. Access your accounts, conduct transactions, and enjoy peace of mind with encryption technology protecting your sensitive information.

Mobile bankingSecure sign-inEncryption technology

by Server Corporation

Test your knowledge of measurement conversions with multiple-choice quizzes. The difficulty increases as your score improves, offering a progressive learning experience.

Multiple choice quizzesMetric to imperial conversionsImperial to metric conversions

Metric Converters

Metric Converters

Metric Converters

Metric Prefix Conversions

Lynbrook High School

Lynbrook High School

Lynbrook High School

Official Mobile Application

Stay informed about school announcements, class updates, and club activities. Manage your schedule with customizable bell schedules and reminders. Earn rewards for school spirit and redeem prizes.

School announcementsClass and club updatesCustomizable bell schedules

Falezo Maids: Length Tools

Falezo Maids: Length Tools

Falezo Maids: Length Tools

by KOCABAS HAKAN KEMAL

Degree Glreds：Unit Manager

Degree Glreds：Unit Manager

Degree Glreds：Unit Manager

by CIFTCI OMER HAKTAN

UnitMate: imperial to metric

UnitMate: imperial to metric

UnitMate: imperial to metric

USA Unit Converter

USA Unit Converter

USA Unit Converter

Widget with Imperial units

SI Prefix Converter

SI Prefix Converter

SI Prefix Converter

Converter: US-Metric Units

Converter: US-Metric Units

Converter: US-Metric Units

Lb-Kg, Cm-Inch, Mi-Km and more

Easily convert between US customary and metric units for weight, length, volume, and temperature. The app features a simple interface with no learning curve and automatically saves your conversion history for quick review.

Weight conversion (Lb-Kg, Oz-G)Length conversion (Cm-Inch, Mi-Km)Volume conversion (Fl Oz-Ml, Cups-L)

free with in-app purchases

Metric/Imperial Units

Metric/Imperial Units

Metric/Imperial Units

by Kraig Wastlund

Easily convert between metric and imperial units for common measurements like temperature, length, mass, and speed. This tool offers a straightforward way to switch between measurement systems.

Imperial to Metric conversionMetric to Imperial conversionTemperature conversion

📊 Productivity

Metric Practice Free

Metric Practice Free

Metric Practice Free

by Carolina Biological Supply

Practice converting between metric prefixes and S.I. units. This app allows you to select units, values, or both to find equivalents. The free version includes novice-level practice for each conversion type.

Metric prefix conversion practiceS.I. unit conversionsSelectable units and values

free with in-app purchases

FAQ about Metric System

What are the best metric system apps for iPhone?

Metric Conversion tool tops our metric system apps ranking as of September 2026, with a 4.8-star average from 15K App Store ratings, and it's free to download.

Are there free metric system apps for iPhone?

Yes — 19 of the top metric system apps we rank are free to download, including Metric Conversion tool and Unit Converter - Best Unit App.

Does Metric Conversion tool have ads or in-app purchases?

Metric Conversion tool has no ads and has no in-app purchases, according to its App Store listing as of September 2026.

How many metric system apps are on the App Store?

We track 250+ metric system apps on the iOS App Store as of September 2026, ranked by rating, recency, and analysis of real user reviews.

What does the Metric Conversion tool app do?

The app is a comprehensive unit and currency converter. It allows users to convert between a vast number of units, including weight, temperature, length, area, volume, speed, time, angle, pressure, and currency. It aims to provide accurate conversion results with a user-friendly interface.

What are the key features of this converter app?

Key features include an easy-to-use interface, offline functionality, support for over 30,000 unit conversions, and over 160 currencies with live exchange rates. It also allows users to store favorite conversions for quick access and provides answers in fractions where needed, with results up to 5 decimal places.