For Mass there are two, four, six or seven altar candles. From the General Instruction of the Roman Missal , n. 117 “In addition, on or next to the altar are to be placed candlesticks with lighted candles: at least two in any celebration, or even four or six, especially for a Sunday Mass or a Holyday of Obligation, or if the Diocesan Bishop celebrates, then seven candlesticks with lighted candles. … The candles and the cross with the figure of Christ crucified may also be carried in the procession at the entrance.”
From Ceremonial of Bishops, n. 1104:
“For exposition of the blessed sacrament in the monstrance, the following are to be prepared:
a. Upon the altar or, in accord with the particular situation, near it:
…
– four or six candles;”
[Excerpt from the English translation of The Roman Missal © 2010, International Commission on English in the Liturgy Corporation. Excerpt from Ceremonial of Bishops © 1989 International Commission on English in the Liturgy Corporation. All rights reserved.]
