In Japan, we use the metric system, so I don't understand the imperial system.
The imperial system is difficult to understand as I am familiar with the metric system.
Metric: Meters, kilograms etc.
Imperial: Feet, pounds etc.
These are the 2 names for the different measurement types.
例：In Japan, we use the metric system, so I don't understand the imperial system.
「日本では、メーター法を使います。なのでインペリアル法はわからないんです。」
例：The imperial system is difficult to understand as I am familiar with the metric system.
「私はメーター法に慣れているので、インペリアル法は理解するのが難しいです。」
メーター法：メーター、キログラム等
インペリアル法：フィート、ポンド等
世界には2通りの単位というものがあります。
Sorry, as a Japanese person, I can only read linear measurements written in the metric system and not in inches, feet and yards.
Please convert these measurements to the metric system equivalents.
Linear measurements written in the metric system are those using millimeters, centimeters, meters and kilometers. The alternative linear measurements are in the imperial system, in inches, feet, yards and miles. Most countries converted to the metric system from the imperial system and students can only understand or read this system of linear measurement. So, if somebody presents to you information that is written in inches, feet and yards, you may say to him/her:
Sorry, as a Japanese person, I can only read linear measurements written in the metric system and not in inches, feet and yards.
or
Please convert these measurements to the metric system equivalents.
メートル法の線形測定値は、ミリメートル、センチメートル、メートル、キロメートルを用いた測定値です。別の線形測定は、インチ、フィート、ヤード、マイルで、帝国単位で行われます。ほとんどの国では、帝国単位からメートル法に変換されているので、メートル法でのみ線形測定値を理解または読み取ることができるでしょう。ですので、もし誰かがインチ、フィート、ヤードで書かれた情報をあなたに伝えた場合は、次のように言うことができます：
Sorry, as a Japanese person, I can only read linear measurements written in the metric system and not in inches, feet and yards.
または
Please convert these measurements to the metric system equivalents.
I don't understand imperial measurements. Are they available in metric?
What are the measurements when they are converted to meters?
Can you convert her height from feet to meters, please?
There are 2 ways in which we can refer to measurements by 'metric' and 'imperial'.Metric is the term used for describing measurements such as centimeters, meters, grams, kilograms, etc. and Imperial is the term we use to describe measurements such as inches, feet, yards, ounces, pounds, etc.
'Convert' means to change from one form to another.
May you please give me the measurements in meters, in Japan we use a metric system
*"May you please give me the measurements in meters, in Japan we use a metric system". - The measurement systems differ from country to country. If given measurements in imperial system and want to change to metric system you will need a conversion table. To convert is to change formats.
"May you please give me the measurements in meters, in Japan we use a metric system."
(メートルの単位を使って教えていただけませんか？日本では、メートル制を使うんです。)
単位の制度が国によって違います。
もし英単位系で単位を言われて、メートル制に変えたければ、
換算表が必要でしょう。
換算して形を変えるためです。
I don't understand feet and inches (as I'm used to metric measurement)
I don't get imperial measurement (as I was brought up using metric)
In context, it's not normally necessary to say: "As a Japanese person," as the person listening will in general already appreciate that you are Japanese, either by obvious physical assessment or by prior knowledge. Regardless of your nationality, there are vast swathes of people around the world not using imperial units (including the UK) so it is not a surprise these days.
文脈的では、 "As a Japanese person," （日本人なので）と必ずしも言う必要はありません。
なぜなら、聞いている人は明らかな身体的特徴を見て、または事前に知っていて、あなたが日本人であることはすでに分かっていることが多いからです。
国籍に関わらず、イギリスを含め、イギリスで使われる単位を使わない人はたくさんいるので、今日では驚かれることではありません。
measurement gauged using the imperial not metric system
example
"i want some wood that's 3 feet long".
this measurement refers to imperial measurement
inches , feet
and the metric being
centimetre and metre
1 inch = 2.54 cm
1 cm = 0.39 inch
例文
"I want some wood that's 3 feet long".
長さが3フィートの木が欲しい。
これは英単位系で表していて、メートル法ではセンチメータルとメートルになります。
1インチ = 2.54 cm
1 cm = 0.39 インチ
"As a Japanese person, it's difficult to understand when things are written in feet"
"In Japan we use meters to measure length, I get confused when units are written in feet"
If you were a Japanese person, and you find it difficult to understand things that are written in feet, you could say either of the following: "As a Japanese person, it's difficult to understand when things are written in feet" or "In Japan we use meters to measure length, I get confused when units are written in feet".
As someone who uses the metric system, it is difficult to understand feet/miles.
metric system
SI units
When saying that it is hard to understand units like miles/feet/etc, you can say: " As someone who uses the metric system, it is difficult to understand feet/miles."
-metric system
This describes the system that most of the world uses where things are measured in meters, kilometers, and so-on. This is also called 'SI units.' SI stands for 'System International' and includes degrees C, kilograms, etc.
南アフリカ 
イギリス 
アメリカ合衆国 
