No. Carat is not the only measure of a diamond’s worth. For example, a six-carat diamond with a ‘flawless’ GIA rating will always be worth more than a seven-carat diamond that’s graded ‘included’, which means its inclusions (flaws) are obvious. Cut is also a factor.
If you’re struggling to understand what factors determine a diamond’s value, take a look at our guide to buying an engagement ring or have a play around with our diamond weight calculator above to see how a diamond’s shape correlates to its weight.