How much to get a card graded depends on four numbers, and only one of them is the fee everybody quotes. Put the per-card fee for your service level, any extras, what it costs you to send the package, and what the grader charges to send it back into the grading cost calculator, and the figure that comes out is the one worth carrying into any decision.
One card is the expensive case
Postage is charged on the package rather than on the card, so a single-card submission carries the whole of it. That is why the per-card cost of sending one card can be several times the fee itself, and why people who grade regularly wait until they have a box rather than sending cards as they find them.
The declared value sets the tier
Graders tier their service levels by the value declared per card, and you must use the tier that matches. Declaring low to save money is not a shortcut: it caps what you can claim if the card is lost or damaged, and graders reserve the right to move a submission to the correct tier and bill the difference. Declare honestly and cost the honest tier.
What the card has to gain
The output that matters is the break-even: what this card must be worth more in a slab than it is raw before the exercise has paid for itself. On a card that sells raw for a few dollars, that hurdle is usually higher than the whole card is worth, which is the arithmetic behind the advice that most cards should never be graded.
Then check the uplift is real
Once you have the cost per card, the grading uplift calculator sets it against the raw price and the price at the grade you expect. Use the price for the grade you will probably get. Costing a submission against the best grade a card could theoretically receive is the commonest way a submission loses money.
Questions people ask about how much to get a card graded
Can I get one card graded cheaply?
The fee for one card is the same as the fee for one card inside a box of twenty; what changes is that the postage is not shared. If cost is the concern, the answer is usually to wait and send several at once.
Do I pay again if I disagree with the grade?
Review and reconsideration services are charged separately where they exist, and the original fee is not refunded. Treat the first submission as the cost of finding out.
Is it cheaper through a group submission?
Submission centres and dealers sometimes pool cards, which shares the postage and can share a bulk rate. That is a real saving on postage and a question of trust about the cards, and it is not something this site has an opinion about.
What should I enter for extras?
Whatever you ticked beyond the base fee: oversized cards, autograph authentication, a reholder, a faster turnaround. They are charged per card, which is how the calculator asks for them.