Dynamic Text size change according to tablet

With all effort,I finally reached to the end of my first app in android. And thanks to all. But after coming to end, I realized one thing that my app text size is common in all tablet sizes. So I will re frame my question.

Problem: I used my own custom text size in entire app. and some what satisfied with 7 inch tablet. But when I am looking the same thing in 8.9 inches and 10.1 inch tablet its containing lots of white spaces and text size are also relatively small. So is there some way that I can change the text size according to my tablet size??? It may look novice question but I am struggling with this because the same app which look wonderful in 7 inches, is loosing its essence in 8.9 and 10.1 inches. Or there is something else which I could do with my app for the same. Probable Solution:- As my topic indicates is there some way to change the text size as tablet size changes. Either dynamically or any other way.

EDITED:: As per Cheeta answer, approach is correct but I can't do it for each layout buttons and textfields and other field. There are hundreds of field like this in single app. Can I do it in some one place and call it required attribute. Is custom tag is approach which I am looking for.Is it possible????

Any help will be appreciated. Thanks in advance.

NOTE I have not reached to a answer but cheetah answer is somewhat leading to correct way. I am marking his answer as correct although there are few alignment issue with his answer. Any other answer is always welcome. Thanks

I was Having Same Problem but what i realized sp/db are not efficient for dealing with this kind of problem, I handled my alignment and font size related stuff programtically.

here are the steps, how i handled this problem.

Calculate Screen Width and Height of Your device
Use Set TextView.setTextSize(unit, size), where the unit parameter is TypedValue.COMPLEX_UNIT_PX and the size parameter is percent of the total width of your screen. Normally, for me, .5% of total width for font is suitable. You can experiment by trying other total width percentages, such as 0.4% or 0.3%.

This way your font size will be always suitable for each and every text/screen size.

After checking some resources I finally came up with the following solution: Within the layout-xml I define the size of the button-text with a dimension declaration:

android:textSize="@dimen/campaign_textfontsize"

I created a dimens.xml in the "/values"-subdirectory with the corresponding value

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <dimen name="campaign_textfontsize">18dp</dimen>
</resources>

then I created a second values-folder "/values-sw720dp" and copied the old dimens.xml into it. In this dimens.xml I adapted the fontsize value:

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <dimen name="campaign_textfontsize">24dp</dimen>
</resources>

Based on the current screensize android selects the proper dimens-value. So without any code, font is adapted to the display- (and display related button-) size.

Hope this helps...

no need to change textsize dynamically use sp for textsize it will automatically arrange the text size depending on the screen resolutions..like in phone.

android:textSize="10sp"

It's quite an old question, but another modern solution can be really handy.
With the Support library, 26+ new text auto sizing is available.
In simple words, you define TextView size and text size gets automatically increased/decreased to match it's bounds:

<TextView
    android:layout_width="match_parent"
    android:layout_height="200dp"
    app:autoSizeTextType="uniform"
    app:autoSizeMinTextSize="12sp"
    app:autoSizeMaxTextSize="100sp"
    app:autoSizeStepGranularity="2sp" />