地球科學工具

Calculate rainfall volume from catchment area and depth, estimate storm runoff with a runoff coefficient, or compute rainfall intensity (mm/hr). Metric and imperial units. Free, instant, browser-based.

Calculate volumetric flow rate Q = A × v for pipes and open channels, estimate flow with Manning's equation, or convert between L/s, GPM, CFS, and m³/s. Metric and imperial units. Free, instant, browser-based.

Calculate river discharge Q from channel width, depth, and mean velocity (velocity–area method), trapezoidal cross-sections with bank slope, or Manning's equation. Results in m³/s, L/s, and CFS with river size classification. Free, browser-based.

Calculate ultimate and allowable soil bearing capacity using Terzaghi's equation for strip, square, and circular footings. Enter cohesion, friction angle φ, unit weight, depth, and footing width. Compare applied pressure to q_allow. Metric and imperial units. Free, browser-based.

Calculate cement, sand, aggregate, and water quantities for concrete mixes. Design by volume, cement bags, or grade presets (M10–M25). Enter mix ratio 1:S:A and water–cement ratio. Metric (m³, kg) and imperial (yd³, lb) units. Free, browser-based.

Calculate steel weight for round bar, rebar, square bar, flat bar, plate, and pipe. Enter dimensions and quantity — get total kg or lb, weight per meter, and volume. Carbon steel density 7850 kg/m³. Metric and imperial units. Free, browser-based.

Calculate pipe flow rate, velocity, friction head loss, and pressure drop. Modes: Q = Av, velocity from flow, Darcy–Weisbach, and Hazen–Williams for water pipes. Reynolds number and flow regime. PVC, steel, and cast iron C presets. Metric and imperial units. Free, browser-based.

Calculate fluid velocity from volumetric flow rate and cross-section geometry. Modes: circular pipe, rectangular channel, annulus, known area, continuity (pipe reducer), and velocity unit converter. Reynolds number and flow regime. Metric and imperial units. Free, browser-based.

Calculate pump hydraulic power, shaft power, and motor sizing from flow rate and head. Modes: hydraulic power (ρgQH), brake power with pump efficiency, motor input with motor efficiency, and power from pressure rise. Results in kW, hp, and W. Water and custom specific gravity. Metric and imperial units. Free, browser-based.