Sometimes saying "I love you" is not enough. This page explains how you can say in Spanish that you love someone so much, very much, and even more...
I love you so much / very much in Spanish
The most common phrases for "I love you" in Spanish are:
Te quiero. (also means I like you and you can use it not only with your spouse or lover, but also with friends or family)
Te amo. (only with your partner/lover).
Here you can see more details on the different variations of "I love you" in Spanish.
Spanish words for "much", "very much", or "so much" that can be used with I love you are especially the following:
"I love you so much" or "I love you very much" is therefore:
Te quiero mucho.
Te quiero tanto.
Te quiero demasiado.
Te amo mucho.
Te amo tanto.
Te amo demasiado.
I love you very very much in Spanish
If you want to express an even greater amount of love, you can use the stronger version of mucho:
Te quiero muchísimo.
Te amo muchísimo.
I love you with all my heart
If very very much is still not enough, you can say "I love you with all my heart":
Te amo con todo mi corazón.
Corazón (heart) is an extremely popular word when talking about love in Spanish. If you have ever seen a telenovela or listened to Spanish love songs, you probably know this word already. One of the popular ways of calling your partner in Spanish is mi corazón (my heart). So you can say:
Te amo mucho, mi corazón.
I love you so much, my heart.
Hopefully you will never need to say that your corazón is broken.
I love you too in Spanish
It is also good idea to have a reply ready, when someone tells you some of the above. Here you can see the various ways of how to say "I love you too" in Spanish.