Does kicker count as part of the spell's converted mana cost?

A spell's mana value (formerly "converted mana cost") is determined solely by the mana symbols printed in its mana cost in the upper-right corner of the card (CR 202.3). Kicker is an additional cost defined under CR 702.33, and paying it does not change the mana cost printed on the card.

Even if you pay a kicker cost, the spell's mana value remains exactly what the printed mana cost totals. Effects that care about mana value — such as cascade or cost-based counters — look only at that printed value, never at any additional costs paid (CR 202.3a).

This also applies to other additional costs like entwine, buyback, or escalate: none of them alter mana value. Only the base mana cost in the mana cost field matters.

Concrete example: Inscription of Ruin has a mana cost of {2}{B}, giving it a mana value of 3. If you pay its kicker cost of {B}{B} to cast it for a total of {4}{B}{B}{B}, its mana value is still 3. A Counterbalance trigger revealing a card with mana value 3 would counter it, not one with mana value 6.