Are old baseball cards worth anything is usually asked about a box found in a loft, and the answer turns on which decade it came from. Age changes two things at once: how many were printed and how many survived in the condition buyers pay for. Neither of those is value on its own.
What age actually does
Print runs grew steadily and then sharply, so a card from the 1950s came out of a far smaller run than one from the 1980s. Older cards were also handled rather than stored, which thinned the surviving population further and left most of what remains in average condition. Both effects push in the direction of scarcity.
Why that is not the same as value
Scarcity only becomes price when somebody wants the card. A common player from a small run is still a card few people are looking for, and it can be genuinely uncommon and still sell for very little. Demand is the second half of the question and it is answered by completed sales rather than by reasoning.
Where the line falls
Roughly 1980. Before that, check cards individually. After it, and particularly from the late 1980s into the mid 1990s, expect common base cards to be worth what postage costs, because production was enormous and collectors stored carefully. It is a rule of thumb about where to spend your time.
How to check one properly
Take your best old card, identify the year and set from the back, find five completed sales of it in similar condition, and run them through the checker. One careful reading calibrates your expectations for the whole box far better than guessing at fifty cards does.
Questions people ask about are old baseball cards worth anything
My cards are from the 1960s but they are worn. Anything?
Possibly, because some early cards sell in any condition. Expect a heavy discount against the sharp examples you see quoted, and read sales for cards that look like yours.
Is a whole old set worth more than the parts?
Rarely for common years and occasionally for early ones, where assembling a complete set is genuinely difficult. The sold record is the evidence.
Should I get old cards appraised?
This site does not appraise and does not recommend appraisers. Reading sales on your best cards will usually tell you what you need faster.
Does storing them properly now help?
It protects what condition remains, which matters if you plan to sell. It cannot recover condition already lost.