Scuba Diving

Calculate straight-line open water swim distance from GPS coordinates. Free online swimming calculator with instant, accurate results.

Calculate swim pace per 100 meters or yards from total time and distance. Free online swimming calculator with instant, accurate results.

Reconcile pace per 100 for one completed, source-labelled swim distance and elapsed-time record without converting course performance or prescribing training.

Calculate a user-entered heart-rate-reserve percentage range with the Tanaka age-estimated maximum. Shows formula and limits; never prescribes training zones.

Reproduce and reconcile the two-point critical swim speed calculation from one source-labelled completed 200 m and 400 m record without prescribing training.

Reconcile a source-labelled swim timing schedule, including every full checkpoint and any final remainder segment, without prescribing race or training pace.

Reconcile one completed adult swimming record with an exact 2024 Compendium code, standard-MET arithmetic, and an independent kcal estimate.

Compare adult BMR equations and a selected activity-multiplier TDEE scenario without generating calorie, macro, or meal prescriptions.

Reconcile a source-labelled latitude/longitude endpoint pair on WGS 84 or GRS 80 with an independent ellipsoidal distance without claiming a route, track, course or swim.

Free online trip budget calculator to estimate vacation costs for flights, hotels, food, and activities. Plan your travel budget before you book anything.

Allocate exactly 100% of monthly income, compare non-negative actual spending, expose fixed-dollar extras, and review transparent balances and planning ratios.

Compare two observed offers on one explicit shared denominator, with auditable unit prices, differences, and a true tie state.

Free online travel expense calculator to track and total trip spending across categories for reimbursement or budgeting. Log flights, meals, and lodging costs.

Calculate a tip, total, and even split for 1–100 people, with optional per-person rounding and a disclosed effective tip percentage.

Free online packing list generator to build travel checklists by trip type, duration, and climate. Never forget essentials on your next vacation again.

Compare equal, guest-night, and custom-unit vacation accommodation splits with exact-cent reconciliation and clear assumptions.

Reproduce gas availability and demand already selected in one named responsible plan, with explicit cylinder, schedule, allowance and independent records—without generating a bottom time or safety approval.

Reproduce final ballast from one completed buoyancy-check record and compare a separate same-unit total without estimating weight or prescribing a dive procedure.

Reproduce pressure-basis SAC and cylinder-specific surface-volume RMV from one named completed segment, matching cylinder rating records, copied average ATA, and an independent RMV check.

Extrapolate wind speed to hub height using logarithmic wind profile. Free online wind energy calculator with instant, accurate results.

Calculate slope angle and grade from rise and run. Free online skiing and snowboarding calculator with instant, accurate results.

Calculate wind chill temperature from air temperature and wind speed. Assess frostbite risk and dress for outdoor running, hiking, and climbing.

Compare row-count, total-decompression-time and final-runtime checkpoints between two records of the same externally prepared decompression schedule while preserving exact source and version context.

Reproduce FO2, nitrogen balance, ppO2 and ppN2 from named analyzed-mixture and ambient absolute-pressure records, then compare two source-owned ppO2 values without selecting limits or approving a dive.

Reproduce surface-gas volume from one completed cylinder pressure window and compare a separate same-unit record without estimating SAC, duration, reserve or dive safety.