wppluginexpert

w2pe Measurement Widget is a simple measurement converter. You can use both in page or widget. There is a possibility to add custom units in admin area and edit or delete units. 
Measurements and units included as presets: 
* Area – foot, inch, meter, mile, kilometer 
* Currency – Bangladeshi TK, British pound, Euro, Indian rupee, Japanese Yen, US dollar 
* Length – kilometer, meter, mile, yard 
* Mass – gram, kilogram, pound, ton 
* Temperature – Celsius, Fahrenheit, Kelvin
<h4>How to use?</h4>
<ol>
<li>If you want to use in widget, use “w2pe Measurement Widget”</li>
<li>If you want to use in a page or post, use [w2pe_measurement]</li>
</ol>

w2pe Measurement Widget

w2pe Measurement Widget is especially designed to make your units conversion job a whole lot easier. Here you'll find instant conversions for tho …

danbwb

Simple to use Unit Converter Plugin for WordPress. It displays both in Metric and Imperial units. For the time, you can use the following categories:
<pre><code>Length / Distance Converter
Temperature Converter
Time Converter
Weight Converter
Area Converter
Speed Converter
</code></pre>
The plugin creates a shortcode so you can display these converters either in posts / pages or inside a sidebar within a text widget.
New features in version 1.1.1
<ul>
<li>Fixed working with jQuery 1.9+</li>
</ul>

Oppso Unit Converter

Simple to use Unit Converter Plugin. It displays both in Metric and Imperial units.

w2pe Measurement Widget vs Oppso Unit Converter