Hi,
We purchased a theme which had this option.
Topic summary
Request to display estimated shipping costs on the product page using customer IP. The initially tried app didn’t work on the store; developer unresponsive after 2–3 days.
Shopify Support suggested an app that shows rates on the cart page (with map and carrier delivery estimates if real-time carriers are set up), plus contacting that app’s developer for product-page placement. Alternatives proposed: Sales Box app or hiring a Shopify Expert for custom implementation.
OP tested the suggested app; it works but needs per-country rules. The original app worked on the default theme but not the active theme. Support advised contacting the theme developer via Online Store > Themes > Customize > Theme Settings > Get support.
Outcome: OP solved it by purchasing the Warehouse theme (Wood style), which includes product-page shipping estimation.
Later updates: new apps announced that show product-page shipping pulled directly from Shopify rates—Musubi’s “Product Page Shipping” and Octolize’s “Product Page Shipping,” the latter offering geolocation via IP, saved address, or mobile GPS.
Open point: A user asked how to show all available rates before checkout (tiered US rates) on product pages; no answer provided in the thread.