I am using AED as my base currency and PayPal is not Supporting AED. i want to convert it in to US Dolor while checkout with PayPal.
If you using multiple currency, you can try this tutorial : Magento Multiple Currency Support For Paypal
Have a look at this module: https://github.com/Meabed/Paypal-Multi-Currency-Magento
This module is for Magento 1.7+ to Support Paypal payments for not supported currencies by PayPal.
Answer provided here as well: https://magento.stackexchange.com/a/79666/1883