Buoyant force
API · /buoyancy-api
Buoyancy & Flotation API
healthy
3,391 Subscribers
Archimedes buoyancy and flotation maths as an API, computed locally and deterministically. The buoyancy endpoint computes the buoyant force on a submerged or floating body, Fb = ρ_fluid·g·V_displaced — the upthrust equals the weight of the displaced fluid — from a displaced volume and a fluid (water, seawater, oil, mercury and more, or a custom density), and also gives the mass of displaced fluid; it solves the volume from a known force too. The float endpoint decides whether an object floats, sinks or is neutrally buoyant by comparing its density (given directly, from a built-in material, or as mass divided by volume) with the fluid density, and for a floating object returns the fraction submerged f = ρ_object/ρ_fluid (so 90 % of an iceberg sits below the waterline), or for a sinking object its apparent (underwater) weight. The payload endpoint sizes flotation: the displaced volume needed to float a given load, V = W/(ρ_fluid·g), or the maximum extra payload a floating body of a given volume and density can carry before it submerges, Wmax = (ρ_fluid − ρ_body)·V·g. Everything is computed locally and deterministically, so it is instant and private. Ideal for naval-architecture and marine tools, diving, ROV and ballast apps, raft and pontoon design, and physics education. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is buoyancy and flotation; for pressure at depth and hydrostatic force on a wall use a hydrostatics API.
api.oanor.com/buoyancy-api
API health
healthy- Uptime
- 100.00%
- Server probes · 24h
- Avg latency
- 77 ms
- Server probes · 24h
- Subscribers
- 3,391
- active
- Total calls
- 80
- last 7 days
Pricing
Pick a tier — billed monthly, cancel anytime.
Free
Free
- 2,000 calls / month
- 2 requests / second
- Hard cap (429 above quota, no overage)
- Buoyant force on fully submerged bodies
- Standard fluid densities (fresh & salt water)
- JSON response with force in newtons
- 2 req/s
Starter
€9.00 /month
- 25,000 calls / month
- 5 requests / second
- Hard cap (429 above quota, no overage)
- Partial-submersion & waterline flotation depth
- Custom fluid density input
- Apparent weight & net force outputs
- 5 req/s
Pro
€24.00 /month
- 150,000 calls / month
- 15 requests / second
- Hard cap (429 above quota, no overage)
- Multi-fluid layered buoyancy
- Stability & metacentric height helpers
- SI + imperial unit handling
- 15 req/s, priority compute
Mega
€75.00 /month
- 750,000 calls / month
- 40 requests / second
- Hard cap (429 above quota, no overage)
- Bulk batch flotation solves
- Full marine fluid-statics suite
- Highest throughput for naval/CAD pipelines
- 40 req/s, SLA-backed uptime
Built by
Related APIs
Other APIs with overlapping tags.
Hot Air Balloon Lift API
Hot-air-balloon lift maths as an API, computed locally and deterministically — the thermal-lift, envelope-temperature and air-density numbers a balloon pilot, designer or physics teacher works a flight out with. The lift endpoint gives the buoyant lift from heating the air: gross lift = envelope volume × (outside air density − inside air density), the densities from the ideal-gas law — a 2,500 m³ envelope at 100 °C on a 15 °C day lifts about 698 kg gross, from which you subtract the envelope, basket, burner and fuel for the payload, and the hotter the air and colder the day the more it lifts. The required-temp endpoint inverts it: to carry a target lift the inside air must reach a particular density and so a particular temperature, with a check that it stays under the ~120 °C that nylon envelopes can take — the everyday pre-flight question of whether the balloon can lift today's crew and fuel. The air-density endpoint gives the moist-air density ρ = (P − 0.378·Pv) ÷ (R·T), and explains the counter-intuitive fact that humid air is LESS dense than dry air, slightly cutting the lift. Everything is computed locally and deterministically, so it is instant and private. Ideal for ballooning and aviation tools, STEM and physics-education apps, and buoyancy calculators. Pure local computation — no key, no third-party service, instant. Idealised dry-lift model. 3 compute endpoints. For Archimedes flotation in water use a buoyancy API; for party-balloon helium lift a balloon API.
api.oanor.com/hotairballoon-api
Hydrostatic Pressure API
Fluid-statics maths as an API, computed locally and deterministically. The pressure endpoint computes the pressure at a depth in a fluid — the gauge pressure ρ·g·h and the absolute pressure (gauge plus atmospheric) — in pascals, kilopascals, bar, psi and atmospheres, for water, seawater, oil, mercury and more, or a custom density; depths accept metres, feet or centimetres, which makes it handy for diving (about 10 m of seawater adds one atmosphere). The force endpoint computes the resultant hydrostatic force on a submerged vertical rectangular surface — an aquarium wall, a tank side, a dam face or a flood gate — as F = ρ·g·h_c·A from its width and the top and bottom depths, and gives the depth of the centre of pressure, which sits below the centroid. The buoyancy endpoint applies Archimedes' principle, F_b = ρ_fluid·g·V, to give the buoyant force and the displaced mass, and — if you supply the object's density or mass — tells you whether it floats or sinks and what fraction sits below the waterline. Everything is computed locally and deterministically, so it is instant and private. Ideal for civil and marine engineering tools, diving and aquarium apps, tank and dam design, and physics education. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is fluid statics; for pump power and head use a pump API and for pipe flow rate use a pipe-flow API.
api.oanor.com/hydrostatic-api
Marine & Surf Forecast API
Marine and surf forecasts as an API, powered by Open-Meteo — clean JSON, no key. Get the current sea state and the hourly and daily wave forecast for any coastline by latitude/longitude or simply by place name: significant wave height, period and direction, plus the swell and wind-wave components broken out separately, and daily maxima and dominant directions. A built-in geocoding helper turns a place name into coordinates. Forecasts run up to ten days ahead. Live forecast data straight from Open-Meteo's marine model. Ideal for surf-report apps, sailing and boating tools, coastal and marine-operations dashboards and beach widgets. 4 data endpoints. Authenticated with an x-oanor-key; fair-use rate limits per plan.
api.oanor.com/marine-api
Sea Horizon API
Sea-horizon and visibility maths as an API, computed locally and deterministically — the distance-to-horizon, geographic-range and dip numbers a mariner, coastal navigator or marine app works sightings with. The horizon endpoint gives the distance to the sea horizon ≈ 1.169·√(height of eye in feet) nautical miles, including the standard atmospheric refraction that bends the line of sight a little past the geometric edge — at 9 ft of eye height the horizon is about 3.5 nm off — together with the dip, how far below true horizontal that watery edge lies (≈ 0.97′·√h), the correction subtracted from a sextant altitude shot to the sea horizon. The geographic-range endpoint gives how far off a light or landmark first peeps over the horizon = the sum of two horizon distances, your own plus the object's: 1.169·(√h_eye + √h_object), so a 100 ft lighthouse from a 9 ft cockpit lifts above the sea at about 15 nm — purely geometric, before the light's own luminous range and the visibility. The object-height endpoint inverts it: how tall a tower, light or headland must stand to break the horizon at a target range, or how close you must be before a known landmark appears. Everything is computed locally and deterministically, so it is instant and private. Ideal for marine-navigation and chartplotter apps, coastal-pilotage and lighthouse tools, and sailing utilities. Pure local computation — no key, no third-party service, instant. Geometric/refraction model. 3 compute endpoints. For great-circle distance use a geo-distance API; for set & drift a set-and-drift API.
api.oanor.com/horizon-api
Frequently asked questions
Quick answers about pricing, quotas, and integration.
How do I get an API key for Buoyancy & Flotation API?
Sign up for free at oanor.com, generate an API key from the developer dashboard, and call Buoyancy & Flotation API with the x-oanor-key header. No credit card needed for the free tier.
What's the rate limit for Buoyancy & Flotation API?
Free tier allows 1 request per second. Paid plans scale up to 50 requests per second on the Mega tier. Hard limits return HTTP 429 above the quota — no surprise overage charges.
How much does Buoyancy & Flotation API cost?
Buoyancy & Flotation API has a free tier with 100 calls / month. Paid plans start at €9.00 / month with higher quotas and faster rate limits.
Can I cancel my subscription anytime?
Yes. Plans are billed monthly and you can cancel anytime from your billing dashboard. No long-term contracts and no cancellation fee.
Is Buoyancy & Flotation API GDPR-compliant?
All requests to Buoyancy & Flotation API go through our EU-based gateway. Your upstream API key never leaves our server and no personal data is shared with the upstream provider beyond the request you send.
Pick an endpoint from the list on the left to see its details and try it.
Code snippets
Sign up to get an API key, then call any path under your slug.
curl https://api.oanor.com/buoyancy-api/SOME_PATH \
-H "x-oanor-key: oanor_test_..."const res = await fetch("https://api.oanor.com/buoyancy-api/SOME_PATH", {
headers: { "x-oanor-key": "oanor_test_..." }
});
const data = await res.json();$ch = curl_init("https://api.oanor.com/buoyancy-api/SOME_PATH");
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, ["x-oanor-key: oanor_test_..."]);
$response = curl_exec($ch);import requests
r = requests.get(
"https://api.oanor.com/buoyancy-api/SOME_PATH",
headers={"x-oanor-key": "oanor_test_..."},
)
print(r.json())Ratings
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