The equivalent FONT SIZE value for BIG text generally used by
browsers is 4 (default FONT size is generally 3.)

FONT SIZE |
size 1 "sample" |
size 2 "sample" |
size 3 "sample" |
size 4 "sample" |
size 5 "sample" |
size 6 "sample" |
size 7 "sample" |
---|---|---|---|---|---|---|---|

BIG |
"sample" | "sample" | "sample" | "sample" | "sample" | "sample" | "sample" |