Estimate Elevation Difference From Contour Intervals
Count spaces between contour levels, not the number of printed lines. Calculate a vertical difference from indexed contours while keeping route distance and travel difficulty out of the answer.
1 · map exercise | lower contour index | upper contour index
FIRST-LOAD
Input is processed locally and a draft is saved automatically in this browser profile when storage is available. Reset to sample clears that draft; Pro history has its own clear button. A state link encodes your inputs in its URL: share only non-sensitive rows. Browser history, clipboard and anyone receiving the link may retain it. Optional AI use below leaves this device; it is not required.
Data note: Everything runs in this browser tab on the relief ladder: your map exercise | lower contour index | upper contour index stays on this device, nothing is uploaded, and the reading is rebuilt only when you press run.
Perspective: Before: Seven spaces separate eight successive contour lines. After: the relief ladder shows the working beside each named row so the reader can change the assumption and inspect the consequence.
2 · Read the relief ladder
Educational arithmetic only, not navigation or outdoor safety advice. Use appropriate maps, skills and current local conditions for real routes.
Paid layer: relief ladder print and history
one-time step · the free reading above stays complete
Free tier
- one complete relief ladder run in the app
- three samples plus unlimited article-demo runs
- unwatermarked result text and an explicit, user-triggered state link
What $4 one-time adds
- print the relief ladder with its row workings
- CSV of vertical metres and row explanations
- last five reading summaries saved in this browser profile
$4 once for repeated filing of the relief ladder, not for a better answer. Illustrative time basis: avoiding one five-minute manual reformat per saved reading; no market-price or guaranteed-savings claim.
Local history (this device)
- No saved runs yet — your first run files here.
Checkout is unavailable until a payment link is configured. The optional unlock is browser-local, profile-scoped and best-effort, not server-verified access. Clearing browser data can remove it; there is no account or cross-device recovery.
Boundary and sources
Educational arithmetic only, not navigation or outdoor safety advice. Use appropriate maps, skills and current local conditions for real routes.
- Method: Upper index minus lower index gives the number of spaces. From index two to nine there are seven intervals, so the sample difference is 140 metres at twenty metres per interval.
- All sample records are invented examples. The app does not fetch measurements, policies, files or personal records.
- Google’s official pricing page, fetched 2026-09-27, lists free-tier access including AI Studio. Optional formatting only; limits and availability can change. Free-tier content may be used to improve products. Never paste private records there.
Mechanism: competence-autonomy-loop
Optional AI formatting, not calculation
For this relief ladder, use the free AI Studio interface only if available to you, with no paid API key. Manual entry completes the same workflow for free. Supply only fictional or non-sensitive notes. Review its output against the source; never paste unresolved questions into the numeric rows.
Format my non-sensitive notes for a relief ladder. Return plain rows only: map exercise | lower contour index | upper contour index. Preserve supplied quantities exactly. Do not guess missing values; list questions separately. Do not calculate or add advice. I will check every row before pasting into the local tool.
Accepted schema: map exercise | lower contour index | upper contour index. No AI response is executed as code.