The image above represents theoretical value of g.

To compute for theoretical value of g, one essential parameter is needed and this parameter is **Latitude (φ).**

The formula for calculating theoretical value of g:

g = (-172 + 136sin²φ)

Where:

g = Theoretical Value of g | Standard Formula

φ = Latitude

Let’s solve an example;

Find the theoretical value of g when the latitude is 18.

This implies that;

φ = Latitude = 18

g = (-172 + 136sin²φ)

g = (-172 + 136sin²(18))

g = (-172 + 136(0.309)²)

g = (-172 + 136(0.0954))

g = (-172 + (12.986))

g = -159.01

Therefore, the **theoretical value of g **is **-159.01 mGal.**

Nickzom Calculator – **The Calculator Encyclopedia** is capable of calculating the theoretical value of g.

To get the answer and workings of the theoretical value of g using the **Nickzom Calculator – The Calculator Encyclopedia. **First, you need to obtain the app.

You can get this app via any of these means:

**Web** – https://www.nickzom.org/calculator-plus

To get access to the **professional **version via web, you need to **register** and **subscribe **for** NGN 2,000 **per** annum** to have utter access to all functionalities.

You can also try the **demo **version via https://www.nickzom.org/calculator

**Android (Paid)** – https://play.google.com/store/apps/details?id=org.nickzom.nickzomcalculator

**Android (Free)** – https://play.google.com/store/apps/details?id=com.nickzom.nickzomcalculator

**Apple (Paid)** – https://itunes.apple.com/us/app/nickzom-calculator/id1331162702?mt=8

Once, you have obtained the calculator encyclopedia app, proceed to the **Calculator Map, **then click on **Geology**** **under **Add-on****.**

Now, Click on **Gravity **under **Geology**

Now, Click on **Theoretical Value of g** under **Gravity**

The screenshot below displays the page or activity to enter your value, to get the answer for the theoretical value of g according to the respective parameter which is the **Latitude (φ)****.**

Now, enter the value appropriately and accordingly for the parameter as required by the **Latitude (φ)** is **18**.

Finally, Click on Calculate

As you can see from the screenshot above, **Nickzom Calculator**– The Calculator Encyclopedia solves for the theroretical value of g and presents the formula, workings and steps too.