The bracket (vertical column) you must use should be based on the highest bracket amount (in the same row as the tax status) that does not exceed your pay.

Example:
In the Weekly Table, if an employee with Z 'zero exemptions' has P2,000 regular pay per week, his bracket tax is P163.46 (+20% over) because P2,000 exceeds the amount 1,346 but does not reach the next amount 2,692.
(Note that 1,346 and 2,692 are both in the same row as Z - the status of the employee. The bracket tax to be used is the one above 1,346.)

Pls. see the Weekly Withholding Tax Table.