| Basic Kestrel dimensions | Main sail |
| Overall length 4.776 metres (15' 7 1/2 in) | Leach length 6401 mm |
| Beam 1.75 metres (5' 6in) | Width – half height 1981 mm including bolt rope |
| Bare hull weight 120 Kg (265 lbs.) | Width – three-quarter height 1245 mm including bolt rope |
| Main 9.29 sq. metres (100 sq. ft.) | Window area 186040 sq. mm |
| Foresail 4.8 sq. metres (52 sq. ft.) | Width – headboard 102 mm |
| Spinnaker 11.15 sq. metres (120 sq. ft.) | Length – top batten 1219 mm |
| Optimum weight 146 Kg (322 lbs.) | Length – lower batten 838 mm |
| Portsmouth Yardstick (PY) 1038 | Width – top batten end (square with luff) 1016 mm |
| Spinnaker | Foresail |
| Hanging height 4572 mm | Luff 4115 mm |
| Greatest width 2896 mm | Leach 4064 mm |
| Half-height width (minimum 3/4 of n) 2896 mm max. | Foot 2413 mm |
| Foot width (n) 2896 mm | Head to half width on foot 4013 mm |
| Maximum roach on leach 102 mm | |
| Window area 186040 sq. mm | |
| Mast | |
| Lower band Upper edge of band above datum on mast: 978 mm – 1004 mm | |
| Upper band Lower edge of band above upper edge of lower band: 5791 mm | |
| Boom band Distance from rear of mast track, to forward edge of limit band: 2730 mm | |
| Spinnaker halyard exit No more than 4013 mm above top edge of lower band |