# Dead load and live load calculator (free) > Need to turn floor build-ups and occupancy into dead and live loads fast? StructLoads is a free tool that computes them and carries them through a full load takedown. **Category:** Fundamentals **Author:** Elena Marchetti (Structural engineer ยท Founder) **Published:** 2026-05-07 --- The quickest way to get your dead and live loads right is to let a tool add up the build-up for you. StructLoads is a free, browser-based dead and live load calculator: you enter the slab and finishes for the [dead load](https://en.wikipedia.org/wiki/Dead_load) and the occupancy for the [live load](https://en.wikipedia.org/wiki/Live_load), and it carries both through a full load takedown to the support reactions. It keeps the two separate so the load factors apply correctly, and it is built for preliminary analysis and learning. ## What the calculator does Most load mistakes are not hard maths; they are a forgotten finish or a wrong occupancy. A calculator that holds the build-up and the occupancy in one place removes those slips. You give it the slab, the finishes and the live load, and it turns them into a [structural load](https://en.wikipedia.org/wiki/Structural_load) per square metre, then multiplies by tributary areas and accumulates down the building. The output is the dead and live reaction at every support. ## Dead and live, kept separate The tool tracks the two load types apart, because the code treats them differently. | Load | What you enter | Typical value | | --- | --- | --- | | Dead | Slab thickness, finishes, services | About 4.5 kPa for a finished 150 mm slab | | Live | Occupancy class | 2.5 to 3.0 kPa office, 1.5 to 2.0 kPa residential | Dead load is the self weight plus finishes; live load is the occupancy. Keeping them separate is what lets the calculator apply the load factors and the live-load reduction correctly, the distinction explained in [dead load vs live load](/blogs/dead-load-vs-live-load-explained). The occupancy values themselves are code minimums with real data behind them; [Ochshorn's live loads chapter](https://jonochshorn.com/structuralelements/book/2.02-live-loads.html) explains how codes assign each occupancy a worst-case value based on observed loading and the historical record of failures. ## A worked example A 150 mm slab is 0.15 times 25, which is 3.75 kPa of self weight. Add 0.75 kPa of finishes and services for about 4.5 kPa of dead load. For an office, take 3.0 kPa of live load plus a 1.0 kPa partition allowance, so 4.0 kPa live. Over a 30 square metre interior column tributary area, that is 135 kN dead and 120 kN live per floor, which the calculator accumulates and factors. The occupancy values come from [typical floor live load values](/blogs/typical-floor-live-load-values-by-occupancy). ## From loads to reactions The point of a load calculator is not the pressure but the reaction. StructLoads multiplies the dead and live pressures by each support's tributary area, accumulates them down the levels, and applies the ASCE 7 or Eurocode combinations, so you get the factored reaction at every column and wall. From the same plan you also get the tributary geometry through the [free tributary area calculator](/blogs/free-tributary-area-calculator), with nothing to install. ## What it does not do A free calculator gets the loads and reactions, but it is a preliminary tool. It does not check member capacity, deflection, lateral loads or connections, and it does not replace a qualified engineer's review or code compliance. Treat its dead and live loads as the fast, checkable starting point for design, then confirm the values and the members against your governing code. ## Key takeaways: dead and live load calculator StructLoads is a free dead and live load calculator: enter the build-up and occupancy, and it computes both and carries them through a takedown to the reactions, keeping dead and live separate. A finished 150 mm slab is about 4.5 kPa dead; an office about 2.5 to 3.0 kPa live. It is preliminary, confirmed by a qualified engineer. ## Quick answers ### Is there a free dead load and live load calculator? Yes. StructLoads is a free, browser-based tool that takes your dead load build-up and occupancy live load and carries both through a full load takedown to the support reactions. You enter the slab, finishes and occupancy; it keeps dead and live separate and applies the load combinations. It is built for preliminary analysis and learning. ### How do you calculate dead and live loads? Dead load is the slab self weight plus finishes, services and fixed partitions, computed from geometry and density; a 150 mm slab with finishes is about 4.5 kPa. Live load comes from the occupancy: an office is about 2.5 to 3.0 kPa. Keep the two separate, because they are factored differently and only live load can be reduced over large areas. ### What dead and live load values should I use? Take dead load from the real build-up: about 3.75 kPa for a 150 mm slab plus 1 to 2 kPa for finishes and services. Take live load from your code by occupancy: roughly 1.5 to 2.0 kPa residential, 2.5 to 3.0 kPa office, 5.0 kPa or more for storage. Confirm the governing values for your project rather than using a rule of thumb. ### Is a free load calculator accurate enough? For preliminary analysis it is, because the arithmetic is exact once the inputs are right; the calculator removes the slips, not the judgement. It is not a substitute for full design, code checking of members, or a qualified engineer's review. Use it to set and check the loads early, then confirm the values and the design against your governing code.