The maximum housing loan amount that Pag-IBIG can grant to a member is Php3,000,000 while the smallest amount is only Php100,000.
Factors that affect the loan amount you will be entitled to:
1. The amount of your contribution
2. Your Net Disposable Income
If you want to avail of a bigger loan amount, you need to increase your contribution and show that your Net Disposable Income is also big enough to cover the monthly amortizations.
The Amount of your Contribution
Here’s a guide: 
Your Net Disposable Income
“A member’s loan entitlement shall be limited to an amount for which the monthly repayment on principal and interest shall not exceed 40% of the member’s net disposable income” – Pag-ibig Primer on Housing Loans
This means that the monthly amortization should not be more than 40% of your net disposable income.
Example:
Net Disposable Income: Php60,000
40% of Php60,000 = Php24,000
(the monthly amortization should not be more than Php24,000)