NZ Post has produced commemorative coins to mark the upcoming coronation of King Charles III.

The series of six coins are minted in silver and gold, including one 11mm gold coin weighing half a gram, and will be released on May 3.

The coins were designed by Stephen Fuller of Wellington and, as is tradition, the King's portrait faced in the opposite direction of Queen Elizabeth II.

The design was personally approved by the King.

There will be six coins, minted in silver and gold, to commemorate King Charles III's coronation. Photo: Supplied / NZ Post.

NZ Post stamps and collectables head Antony Harris says King Charles III will be the first king of New Zealand to appear on the country's decimal currency.

"It is fitting that the first appearance of His Majesty's effigy will be on coins commemorating the coronation."

New Zealand coins have always featured a portrait of the reigning monarch, beginning with King George V in 1933 when New Zealand coinage was first introduced to replace British currency.

NZ Post will also issue stamps to commemorate the coronation, including a sheet featuring images from the coronation ceremony on May 6.

-RNZ.