I've developed a simple web-based tool to experiment with outfittings and calculate jump ranges, buy/rebuy costs, etc.

Try it out here: http://www.edshipyard.com

I can't yet buy any of the larger ships so the ship and module data is limited to what's available on the wiki; I'll add more as people send me data. If you'd like to help, see this thread for an up-to-date list of the data I'm still missing.

Changelog
2015-01-05 v0.1 : first release
2015-01-06 v0.2 : added power usage for class 1-4 distributors and most class 1-6 internals
2015-01-07 v0.3 : added address bar hashes to post and share loadouts
2015-01-08 v0.4 : added Python support; export to text; power and cost toggles
2015-01-09 v0.5 : Imperial Clipper support; cargo hatch power toggle; corrected power usage of all distributors; a few class 3 weapons and class 7 internals
2015-01-11 v0.6 : Type-9 and Anaconda support; various module additions and corrections
2015-01-13 v0.7 : new domain name; a few more modules; bugfixes; page load performance tweaks
2015-01-14 v0.8 : Federal Dropship support; fixed jump ranges for 6B and 6A FSDs
2015-01-22 v0.9 : Orca support; export with stats; improved localized number formatting
2015-01-27 v0.9.1 : fuel-smart route planner; import from text; some missing module stats
2015-01-30 v0.9.2 : improved route planner accuracy for advanced cost optimization
2015-02-12 v1.1.0 : some data updates for EDv1.1; better annotation of missing data to encourage folks to submit it
2015-02-23 v1.1.1 : import from text is more fault tolerant; more data updates and corrections for EDv1.1
2015-03-04 v1.2.0 : added new ships and modules from EDv1.2; added and corrected many existing ship and module stats
2015-03-11 v1.2.1 : EDv1.2 ship and module prices and stats; reserved internal compartments on the Orca
2015-03-13 v1.2.2 : fixed Shield Booster stacking; updated some ship, bulkhead and fuel prices; added Detailed Surface Scanner range
2015-03-16 v1.2.3 : updated effective shield strength calculations based on developer posts
2015-03-30 v1.2.4 : added 3C/G Cannon; power use percentages now round up; unlocked the Orca's internals; moved the Cargo Hatch to its own line
2015-05-28 v1.3.0 : added new ships and modules from EDv1.3; added, updated and corrected many existing ship and module stats
2015-06-11 v1.3.1 : added ship mass lock factors; corrected Courier bulkhead mass
2015-08-17 v1.3.2 : added Power-specific weapons and modules
2015-09-01 v1.4.0 : added new ships from EDv1.4; updated sensor ranges; added Diamondback Explorer mass lock factor
2015-09-02 v1.4.1 : changed the shield strength formula; changed dropdown colors
2015-09-10 v1.4.2 : added thruster speed modeling and ship discount price modeling; corrected ship speed and Prismatic shield strength values
2015-09-22 v1.4.3 : further improved engine/boost modeling; added SCB charge amounts; tidied up Ship attributes display
2015-10-07 v1.4.4 : updated all ship and module prices; added rank requirements for faction ships
2015-11-13 v1.5.0 : added new ships and modules from EDv1.5
2015-12-26 v2.0.0 : added/updated new/changed ships and modules from EDv2.0
2016-05-26 v2.1.0 : added weapon damage and capacitor modeling and profiling; added/updated new/changed modules and attributes from EDv2.1
2016-06-22 v2.1.1 : added huge Burst Lasers; updated all Power Distributors (the eng/sys buff from 2.1 was reverted)
2016-10-25 v2.2.1 : added engineer modifications, power management, saved loadouts, perfected shield and thruster modeling, Coriolis and Companion API import, drag+drop import, improved module pickers, and ship and module updates from EDv2.2
2016-10-26 v2.2.2 : improved API imports; updated the Pack-Hound Missile Rack
2016-10-30 v2.2.3 : added more API import modifiers; updated a few module attributes; miscellaneous bug fixes
2016-11-07 v2.2.4 : added attribute modifier sliders; added more API import modifiers; added Coriolis(EDCD) import modifications support
2016-11-17 v2.2.5 : added more API import modifiers; fixed a potential bug with direct imports from EDMC
2016-12-09 v2.2.6 : added blueprints and preset rolls, stored modules, and icon graphics; added and corrected various API import modifiers
2017-01-13 v2.2.7 : updated for EDv2.2.03: added Military Compartments and MRPs; various module and blueprint updates
2017-04-11 v2.3.0 : updated for EDv2.3.0: added Dolphin, crew seats, new sensor/scanner blueprints, and turreted Mining Lasers; various ship, module and blueprint updates
2017-04-24 v2.3.1 : fixed and updated route plotter to use EDSM for the latest starmap data instead of the now-defunct EDSC
2017-09-26 v2.4.0 : updated for EDv2.4.0: added Repair Limpet Controllers, updated support for FD's new format for engineer modifications in API loadout imports
2017-10-03 v2.4.1 : added Xeno Scanner and AX Missile Racks
2017-10-06 v2.4.2 : added AX Multi-cannons, fixed importing modifications to Burst Size and Burst ROF (i.e. Double-shot frag cannons)
2017-10-12 v2.4.3 : added Remote Release Flak Launcher, fixed importing modifications to clip size
2017-10-19 v2.4.4 : added Shutdown Field Neutraliser; added support for importing the Plasma Slug special effect; added imported data dump to the "unsupported modification" warning popup
2017-12-20 v2.4.5 : added Type-10 Defender and medium size AX Multi-cannons and AX Missile Racks; added support for importing a few more engineering special effects
2017-12-30 v2.4.6 : fixed Type-10 import and mass lock; fixed long range falloff modification; disabled rate of fire import warning
2018-01-16 v2.4.7 : added Decontamination Limpet Controllers; enabled fitting of undersized Thruster and Shield Generator modules (reporting zero thrust or shield strength if their maximum mass is exceeded, but allowing for engineering modifications to make them usable)
2018-02-27 v2.5.0 : updated for EDv3.0.0: added Alliance Chieftain, Tech Broker modules and Recon Limpets, updated Type-7, Type-9, Type-10 and engineering blueprints