Auction houses employ a meticulous process to estimate the value of bronze sculptures before sale, combining expertise, research, and market analysis. Key factors include the artist's reputation—works by renowned sculptors like Rodin or Giacometti command higher prices. Provenance, or the sculpture's ownership history, also plays a critical role; pieces with documented ties to notable collections or exhibitions often fetch premium values.

The sculpture's condition is another vital consideration. Auction specialists examine wear, patina, and restoration work, as flaws can significantly impact value. Additionally, rarity and demand influence estimates—limited-edition or unique pieces attract competitive bidding.

Market trends are analyzed to align estimates with current buyer interest. Auction houses review recent sales of comparable works, adjusting for economic conditions and collector preferences. Finally, scientific testing may verify authenticity, ensuring the bronze's age and composition match the artist's era.

By synthesizing these elements, auction houses provide accurate, market-driven estimates that guide both sellers and buyers in the dynamic world of art auctions.