Kate celebrates her birthday today, but how old is the duchess?

Kate Middeleton celebrates her 39th birthday today.

The royal family has shared a photo of the duchess to congratulate her on her 39th birthday. The image was posted on Clarence House's Instagram page with the message: "Happy Birthday Duchess of Cambridge!"

The photo was taken last September when Kate was holding a gold pendant dedicated to her three children. The pendant is engraved with the letters 'G, L, C' in honor of Prince George, Princess Charlotte and Prince Louis.

While on the Duke and Duchess of Cambridge Instagram account, as a birthday homage, a photo of Kate wearing a floral face mask was posted.

"Thank you for your good wishes on the Duchess's birthday. "Birthdays have been very different in recent months and our thoughts continue to be with all those who work on the front line in this extremely difficult time," the caption read.

Due to the isolation from the pandemic, Kate's birthday will be different from any other year, without major celebrations and gatherings. The Duchess is with the family at their home in Norfolk, Anmer Hall, where they spent Christmas.