Facebook Twitter Instagram Youtube Pinterest tumblr
r1 = outer radiusr2 = inner radiusC1 = outer circumference C2 = inner circumference A1 = area of circle of r1, area within outer circleA2 = area of circle of r2, area within inner circleA0 = shaded area, outer area minus inner areaA0 = A1 - A2π = pi = 3.1415926535898 √ = square root
This online calculator will find the area, circumference and radii of an annulus. With any 2 known variables you can calculate the other 5 unknowns. Use the following formulas and sets of equations below to calculate measures of an annulus.
Area of the annulus between r1 and r2, the shaded area, is the area contained by the outer circle minus the area contained by the inner circle or A0 = A1 - A2. You will need to know 2 elements in order to calculate the remaining variables.
Units: Note that units of length are shown for convenience. They do not affect the calculations. The units are in place to give an indication of the order of the calculated results such as ft, ft2 or ft3. Any other base unit can be substituted.
C1 = 2πr1
C2 = 2πr2
A1 = πr12
A2 = πr22
A0 = A1 - A2
The following are the sets of formulas we used in our calculations:
Remember my nickname and email for next time.
Email address will not be shared with or sold to any third parties
It might also interest you
We use cookies to help you navigate efficiently and perform certain functions. You will find detailed information about all cookies under each consent category below. The cookies that are categorised as ”Necessary” are stored on your browser as they are essential for enabling the basic functionalities of the site.
We also use third-party cookies that help us analyse how you use this website, store your preferences, and provide the content and advertisements that are relevant to you. These cookies will only be stored in your browser with your prior consent. You can choose to enable or disable some or all of these cookies but disabling some of them may affect your browsing experience. By clicking “Accept”, you consent to the use of cookies as described in our Privacy Policy.
Necessary cookies are required to enable the basic features of this site, such as providing secure log-in or adjusting your consent preferences. These cookies do not store any personally identifiable data.
Functional cookies help perform certain functionalities like sharing the content of the website on social media platforms, collecting feedback, and other third-party features.
Analytical cookies are used to understand how visitors interact with the website. These cookies help provide information on metrics such as the number of visitors, bounce rate, traffic source, etc.
Performance cookies are used to understand and analyse the key performance indexes of the website which helps in delivering a better user experience for the visitors.
Advertisement cookies are used to provide visitors with customised advertisements based on the pages you visited previously and to analyse the effectiveness of the ad campaigns.