A calculator hub needs pages with different inputs, methods or interpretation.
Require a distinct calculation or decision
A calculator hub needs pages with different inputs, methods or interpretation. A cost page can justify separate price inputs. A second URL created by adding free or online to the same tool does not provide that distinction.
Build the explanation around the actual engine
Publish the formula, input units, worked example and limitations for the function on the page. Test a normal case and a changed-input case. Correct an unsupported feature claim before expanding the copy. More words cannot compensate for a calculation that does not match its explanation.
Connect the next useful step
Link a quantity calculation to a relevant cost estimate or purchasing checklist. Use category navigation for discovery and contextual links for the immediate decision. Keep duplicate variants assigned to their verified canonical parent. Include eligible published pages in the sitemap and review real crawling and indexing evidence after release.